14.1. CANopen Overview¶

CANopen is a real-time, high-speed CAN-based protocol specified by CiA (CAN in Automation) for communicating among multiple nodes. CANopen networks are formed using twisted-pair cabling, where all network nodes can be directly wired together through D-sub connectors.

CANopen EDS (electronic datasheet) files are used to describe the communication parameters and object dictionary of CANopen nodes. Magna-Power Electronics provides this EDS file to customers which contains identifying information, supported communication objects, and parameter settings.

Magna-Power Electronics has implemented basic process data objects (PDOs) for use with our products. Customer PDO remapping is not supported. Layer setting services (LSS) is supported to change the node ID and baud rate of each node.

14.2. Physical Interface¶

../../../../../../_images/can-physical-interface.svg

Fig. 14.1 Rear interface¶

14.2.1. D-sub 9 Port¶

The ALx Series has a single, male D-sub 9 port on the rear of the unit for CANopen communications, shown in Rear interface labeled CANOPEN. The pinout for the D-sub 9 port is as follows:

Pin 2: CAN_L
Pin 3: CAN GND (isolated)
Pin 5: Shield GND
Pin 7: CAN_H

14.2.2. LED Codes¶

In the rear of the ALx Series is a communications interface with two exposed bi-color LEDs. The LED labeled RUN indicates status of the CANopen device and the one labeled ERR indicates CANopen communication errors, as shown in Rear interface. Status is indicated using colors and blink patterns, as shown in the tables below.

Table 14.1 RUN LED States¶
State	Description
Off	No power or initializing
Green	Online, operational state
Green, flashing	Online, pre-operational state
Green, 1 flash	Online, stopped state
Green, rapid flickering	Baud rate detection or LSS in progress
Red	Fatal event

Table 14.2 ERR LED States¶
State	Description
Off	No power or no error
Red, 1 flash	Bus warning limit reached
Red, 2 flashes	Error control event
Red, rapid flickering	LSS in progress
Red	Bus off (fatal event)

14.3. Data Objects¶

14.3.1. Process Data Objects (PDOs)¶

PDOs are real-time data frequently sent to and from connected Magna-Power Electronics nodes. When describing PDO traffic, it is referenced with respect to the CANopen slave node. For example, Transmit PDOs (TPDO) are transmitted from the slave and are read-only, while Receive PDOs (RPDO) transmits variables to the slave and have write access. Measurement readings would be mapped in the TPDO Mapping, whereas set points would be in the RPDO Mapping.

14.3.2. Service Data Objects (SDOs)¶

SDOs are messages sent on request and have no timing expectations. SDOs are intended for non-real-time communications, as they must wait for the network to respond. They are typically used for reporting the node status, changing operating modes, etc. SDOs variables should not be used to update values already part of a PDO, as they are updated regularly, and the values would be overwritten by the PDO.

14.4. CANopen State Machine¶

The master controls slaves by following the CANopen state machine. Slaves can transition between four states: Init, Pre-Operational, Operational, and Stopped. In each state, configuration checks are made and different types of communications are allowed. The transition between states are diagrammed in CANopen state machine. Allowed communications in each state is described in Allowed protocols for each state. Nodes enter Init when first switched-on and reach Operational under normal conditions.

Fig. 14.2 CANopen state machine¶

Table 14.3 Allowed protocols for each state¶
State	RSDO/TSDO	TPDO	RPDO
Init
Pre-Operational	✓
Operational	✓	✓	✓
Stopped

14.5. CANopen Default Node Settings¶

The default settings for Magna-Power Electronics CANopen nodes are as follows:

Node ID: 0x70
Data rate: 10 kbps

These settings can be changed using Layer Setting Services (LSS). The exact procedure for changing these settings is device-specific and can be found in your PLC’s user manual. The details needed to reconfigure Magna-Power Electronics CANopen nodes are found in Node details for LSS. Note that the serial number is a unique identifier for each node and can be found printed on on the product label or through the about menu. The serial used for LSS is the part of the serial number that is listed after the - symbol in the product’s serial number.

Table 14.4 Node details for LSS¶
Property	Value
Vendor ID	0x0000001B
Product Code	0x0000000D
Revision Number	0x00010002
Serial Number	product serial (32-bit)

14.6. Development using Python¶

Communication with Magna-Power Electronics CANopen nodes can be done using the canopen Python library. The library allows for communication using CANopen and can be used to read and write data to CANopen nodes. The library is available for download on the Python Package Index (PyPI) using the link: canopen

A compatible CAN interface is needed. A full list of compatible interfaces is listed in the canopen library’s documentation, found here. Internally, Magna-Power Electronics uses the Seeed Studio USB to CAN Analyzer (114991193) for its CANopen development and testing.

14.6.1. Device Setup¶

Ensure that the canopen library and any necessary drivers are installed on your system. In order to correctly access the node’s object dictionary, Magna-Power Electronics supplies an EDS file with your CANopen product.

Magna-Power Electronics EDS File

The following code snippet shows how to create a CANopen network and connect to a node with the default node ID of 0x70 and data rate of 10 kbps. Ensure that the bus type and channel are set to the correct values for your interface. This code snippet also assumes that the EDS file is in the same directory as the script.

import canopen

# Set the interface port and bitrate
INTERFACE_PORT = 'COM7'
BITRATE = 10000

# Create a CANopen network and connect to the node
network = canopen.Network()
network.connect(bustype='seeedstudio', channel=INTERFACE_PORT, bitrate=BITRATE)
mpeNode = canopen.RemoteNode(0x70, 'mpe_canopen.eds')
network.add_node(mpeNode)

# Set the SDO response timeout to 2 seconds
mpeNode.sdo.RESPONSE_TIMEOUT = 2

# Set the state of the node to pre-operational
 mpeNode.nmt.state = 'PRE-OPERATIONAL'

# Add code here to read/write data to the node

network.disconnect()

14.6.2. SDO Communication¶

The available SDO variables are listed in the Manufacturer Specific Service Data Objects section. The following code snippet shows how to read and write to an SDO variable.

# Read from an SDO variable
current = mpeNode.sdo['MeasCurrQ'].raw

# Write to an SDO variable
mpeNode.sdo['SetpointCurr'].raw = 1.5

For SDO variables with multiple subindices, the subindex can be accessed using the following syntax:

status0 = mpeNode.sdo["StatusRegQ"][1].raw
status1 = mpeNode.sdo["StatusRegQ"][2].raw

14.6.3. PDO Communication¶

The available PDO variables are listed in the Manufacturer Specific Process Data Objects section. Before enabling PDO communication, the PDO configuration must be read from the node. The following code snippet shows how to read the PDO configuration from the connected node.

# Read PDO configurations from node
mpeNode.tpdo.read()
mpeNode.rpdo.read()

Note that TPDO data is the data transmitted by the Magna-Power Electronics node, while RPDO is the data received by the node.

There are two main ways to access PDO data: using the sync method or by using up an event timer. The sync method` is used to sync the PDO data with the node when a sync command is sent by the master, while the event timer` is used to specify the interval at which the node should transmit and receive its PDO data. The following code snippet shows how to setup the sync method to read PDO data and print to the console. Note that sync commands can be sent manually, or at fixed intervals as shown in the code.

# Set TPDO 1's transmit mode to sync
mpeNode.sdo['TPDO communication parameter 1']['Transmission type'].raw = 1

# Send a single sync command to the node
network.sync.transmit()

# Set up sync timer for automatic sync transmission
network.sync.start(0.25)  # Sync every 0.25 seconds

# Change state to operational (NMT start)
mpeNode.nmt.state = 'OPERATIONAL'

The following code snippet uses an event timer to automatically transmit the data without the need for a sync command:

# Set TPDO 1's transmit mode to be internal-event triggered
mpeNode.sdo['TPDO communication parameter 1']['Transmission type'].raw = 255

# Set event timer to 250 ms
mpeNode.sdo['TPDO communication parameter 1']['Event timer'].raw = 250

# Change state to operational (NMT start)
mpeNode.nmt.state = 'OPERATIONAL'

14.6.4. Layer Setting Services (LSS)¶

Layer setting services (LSS) can be used to change the node ID and data rate of a target CANopen node to meet the demands of your network. There are two possible states for LSS: configuration and waiting. In the configuration state, the LSS master can change the node ID and data rate of the node. In the waiting state, the node operates normally.

There are two methods to bring a node into the configuration state. The first method is selective and requires knowledge of the connected node’s properties. These include the vendor ID, product code, revision number, and serial number. The default values for these properties can be found in Node details for LSS. To selectively request the node to enter the configuration state, the following code snippet can be used:

network.lss.send_switch_state_selective(vendorId=0x1B, productCode=0xD, revisionNumber=0x10002, serialNumber=SERIAL_NUMBER)

If the node’s properties are not known, users can globally request all connected nodes to enter the configuration state. The following code snippet can be used to globally request all connected nodes to enter the configuration state:

network.lss.send_switch_state_global(network.lss.CONFIGURATION_STATE)

Once a node is in the LSS configuration state, the node ID and data rate can be changed. The following code snippet shows how to change these settings:

# Change the node ID to 0x71
network.lss.configure_node_id(0x71)

# Change the data rate to 500 kbps
network.lss.configure_bit_timing(2)

Note that when setting the node ID, only one node should be connected to the CANopen network to prevent address conflicts. This node ID can be set to any value between 0x01 and 0x7F. Data rates are set based on bit-timing values, as shown in Bit timing values for different data rates.

Table 14.5 Bit timing values for different data rates¶
idx	Data rate
8	10 kbps
7	20 kbps
6	50 kbps
5	100 kbps
4	125 kbps
3	250 kbps
2	500 kbps
1	800 kbps
0	1 Mbps

Finally, once the node is configured, the settings can be saved and the nodes can be brought back into the operational state using the following code snippet:

network.lss.store_configuration()
network.lss.send_switch_state_global(network.lss.WAITING_STATE)

14.7. Standard Object Dictionary¶

The physical interface to a CANopen network is performed with an industrial communication module installed internal to the ALx Series. The module complies with version 4.2.0 of the CiA 301 specification. This specification calls for services and standard data object implementations outlined in the reference material below. The data objects reside in allocated address space shown in Data object dictionary

CiA 301

Network Interface Appendix Anybus CompactCom CANopen Doc.Id. SCM-1202-108

Table 14.6 Data object dictionary¶
Index	Object
0x0000	Reserved
0x001-0x025F	Data types
0x0260-0x0FFF	Reserved
0x1000-0x1FFF	Communication profile area
0x2000-0x5FFF	Manufacturer specific profile area
0x6000-0x9FFF	Standardized device profile area
0xA000-0xBFFF	Standardized interface profile area
0xC000-0xFFFF	Reserved

14.8. Manufacturer Specific Instances Listing¶

CANopen Command	Write Index	Read Index	Description
Operation Commands
StatusQuesQ	N/A	0x200B	Returns the value of the Questionable Status register
StatusOperQ	N/A	0x200C	Returns the value of the Operation Status register
StatusRegQ	N/A	0x200D	Status Register
Input	0x2011	0x2012	Enables or disables the DC input based on parameter setting
Measurement Commands
MeasCurrQ	N/A	0x2101	Measures and returns the average current at the sense location
MeasVoltQ	N/A	0x2102	Measures and returns the average voltage at the sense location
MeasPwrQ	N/A	0x2103	Measures and returns the instantaneous DC power at sense location
MeasResQ	N/A	0x2104	Measures and returns the instantaneous resistance at sense location
Setpoint Commands
SetpointCurr	0x2201	0x2202	Sets the current set-point
SetpointVolt	0x2203	0x2204	Sets the voltage set-point
SetpointPwr	0x2205	0x2206	Sets the power set-point
SetpointRes	0x2207	0x2208	Sets the resistance set-point
Trip Commands
OverTripCurr	0x2301	0x2302	Sets the over current trip (OCT) set-point
OverTripVolt	0x2303	0x2304	Sets the over voltage trip (OVT) set-point
OverTripPwr	0x2305	0x2306	Sets the over power trip (OPT) set-point
UnderTripVolt	0x2307	0x2308	Sets the under voltage trip (UVT) set-point
Slew Commands
RiseRampCurr	0x2401	0x2402	Sets the rising slew rate for current when in current regulation state
RiseRampVolt	0x2403	0x2404	Sets the rising slew rate for voltage when in voltage regulation state
RiseRampPwr	0x2405	0x2406	Sets the rising slew rate for power when in power regulation state
RiseRampRes	0x2407	0x2408	Sets the rising slew rate for resistance when in resistance regulation state
FallRampCurr	0x2409	0x240A	Sets the falling slew rate for current when in current regulation state
FallRampVolt	0x240B	0x240C	Sets the falling slew rate for voltage when in voltage regulation state
FallRampPwr	0x240D	0x240E	Sets the falling slew rate for power when in power regulation
FallRampRes	0x240F	0x2410	Sets the falling slew rate for resistance when in resistance regulation state
Control Commands
ControlMode	0x2503	0x2504	Sets the control mode
Function Generator Commands
FuncType	0x2601	0x2602	Sets the desired function for the integrated function generator
FuncSinAmpl	0x2603	0x2604	Sets the amplitude for the sinusoid function
FuncSinOff	0x2605	0x2606	Sets the DC offset from zero for the sinusoid function’s midline
FuncSinPrd	0x2607	0x2608	Sets the period for the sinusoid function
FuncSquLoLevel	0x2609	0x260A	Sets the low level amplitude for the square function
FuncSquHiLevel	0x260B	0x260C	Sets the high level amplitude for the square function
FuncSquLoPrd	0x260D	0x260E	Sets the period that the square function remains at the low level amplitude
FuncSquHiPrd	0x260F	0x2610	Sets the period that the square function remains at the high level amplitude
FuncStepLoLevel	0x2611	0x2612	Sets the low level amplitude for the step function
FuncStepHiLevel	0x2613	0x2614	Sets the high level amplitude for the step function
FuncRampLoLevel	0x2615	0x2616	Sets the low level amplitude for the ramp function
FuncRampHiLevel	0x2617	0x2618	Sets the high level amplitude for the ramp function
FuncRampRisePrd	0x2619	0x261A	Sets the period for the ramp function to transition from low to high level amplitude
FuncRampFallPrd	0x261B	0x261C	Sets the period for the ramp function to transition from high to low level amplitude
Configuration Commands
FactoryRestore	0x2701	N/A	Restores the factory EEPROM data
Lock	0x2703	0x2702	Locks and unlocks the product from configuration and set-point changes
SenseMode	0x2706	0x2707	Configures the sense location and automated compensation values
CommProt	0x2708	0x2709	Changes the communication protocol
SetSource	0x270A	0x270B	Sets the setpoint source
MagnaLinkMode	0x270C	0x270D	Changes the MagnaLINK mode to allow for standalone or master-slave configuration
MagnaLinkReinit	0x270E	N/A	Reinitialize all connected slaves
CoolingMode	0x270F	0x2710	Sets the cooling mode

14.9. Manufacturer Specific Process Data Objects¶

14.9.1. Operation Commands¶

14.9.2. StatusRegQ¶

This command queries the Status Register. This read-only register holds the live (unlatched) operation status of the MagnaLOAD electronic load. Issuing a query does not clear the register. The register location and definitions are subject to change after any firmware release to accommodate new features. The Questionable Register is a subset of the status register and does not change between firmware updates. The present bit assignments are shown in the table below.

Access: RO
Data Format: 32-bit Integer

Status Register 0

Bit	Name	Description
0	standby	output is in standby
1	live	output is active
2	solenoidStatus	aux power solenoid is open
3	nonhalt2	available
4	overCurrTrip	over current trip
5	overVoltTrip	over voltage trip
6	overPwrTrip	over power trip
7	remoteSenseLoss	remote sense voltage outside of acceptable bounds
8	underVoltTrip	under voltage trip
9	shutdown	target is creating a shutdown condition
10	linPwrLim	power across linear modules exceed ratings
11	resPwrLim	power across resistors exceed ratings
12	bootFailure	one or multiple target did not boot up
13	bootState	one or more targets are waiting to boot
14	phaseCurr	rated phase current exceeded
15	comm	communications are corrupted
16	overCurrProtect	terminal current exceeded product rating
17	overVoltProtect	terminal voltage exceeded product rating
18	tempRLin	linear module exceeded temperature
19	blownFuse	fuse is blown on the auxiliary power supply
20	interlock	interlock open
21	haltUserClear	available
22	maintenance	maintenance
23	tempDMod	diode modules exceeded temperature
24	incompatibleSysConfig	incompatible system configuration
25	stackOverflow	exceeded firmware stack
26	lineFault	line fault analog/digital inputs
27	tempRMod	resistor module exceeded temperature
28	belowRatedMinVolt	below minimum voltage rating(28)
29	outOfRegulation	out of regulation, unexpected currents measured
30	targetUpgrade	mainctrl upgrading other targets
31	haltSelfClear	available

Status Register 1

Bit	Name	Description
0	phaseLoss	one or more phase missing
1	blownFuseInput	input fuse blown on fuse/emi filter
2	fanLockedRotor	one or more fan’s rotor has locked
3	notUsed29	available
4	tempPwrMod	power processing module temperature fault
5	tempOutputMod	output filter module temperature fault
6	tempOutputCap	output capacitors temperature fault
7	tempTransformer	transformer exceeded temperature fault
8	notUsed26	available
9	notUsed27	available
10	notUsed28	available
11	notUsed1	available
12	notUsed2	available
13	notUsed3	available
14	notUsed4	available
15	notUsed5	available
16	invalidSysRating	invalid system rating
17	fwVersConflict	firmware version conflict
18	notUsed8	available
19	notUsed9	available
20	notUsed10	available
21	notUsed11	available
22	notUsed12	available
23	notUsed13	available
24	notUsed14	available
25	notUsed15	available
26	notUsed16	available
27	notUsed17	available
28	notUsed18	available
29	notUsed19	available
30	notUsed20	available
31	notUsed21	available

14.9.3. Measurement Commands¶

14.9.4. MeasCurrQ¶

This query commands the MagnaLOAD electronic load to measure and return the average current through the DC terminals.

Access: RO
Data Format: 32-bit Floating Point Number

14.9.5. MeasVoltQ¶

This query commands commands the MagnaLOAD electronic load to measure and return the average voltage at the DC terminals. If the remote sense function is used and engaged, this command returns the voltage measured at the sense terminals.

Access: RO
Data Format: 32-bit Floating Point Number

14.9.6. Setpoint Commands¶

14.9.7. SetpointCurr¶

This command programs the current set-point that the MagnaLOAD electronic load will regulate to when operating in constant current mode.

Access: RW
Data Format: 32-bit Floating Point Number

14.9.8. SetpointVolt¶

This command programs the voltage set-point, in volts, which the MagnaLOAD electronic load will regulate to when operating in constant voltage mode.

Access: RW
Data Format: 32-bit Floating Point Number

14.10. Manufacturer Specific Service Data Objects¶

14.10.1. Operation Commands¶

14.10.1.1. StatusQuesQ¶

This command queries and returns the values of the Questionable Register. This read-only register holds the live (unlatched) questionable statuses of the MagnaLOAD electronic load. Issuing this query does not clear the register. The bit configuration of the Questionable Register is shown in the table below.

Index: 0x200B
Access: RO
Data Format: 32-bit Integer

Questionable Register

Bit	Weight	Abbreviation	Description
0	1	OVP	over voltage protection, hard fault
1	2	OCT	over current trip, soft fault
2	4	OVT	over voltage trip, soft fault
3	8	OPT	over power trip, soft fault
4	16	OCP	over current protection, hard fault
5	32	OTP	over temperature protection, hard fault
6	64	RSL	remote sense loss, soft fault
7	128	SFLT	soft fault, the ord value of all soft faults
8	256	HFLT	hard fault, the ord value of all hard faults
9	512	ILOC	interlock open, soft fault
10	1024	IPL	input power loss fault, hard fault
11	2048	ADIF	analog or digital input fault, hard fault

14.10.1.2. StatusOperQ¶

This command queries and returns the values of the Operation Register. This read-only register holds the live (unlatched) operation statuses of the MagnaLOAD electronic load. Issuing this query does not clear the register. The bit configuration of the Operation Register is shown in the table below.

Index: 0x200C
Access: RO
Data Format: 32-bit Integer

Operation Register

Bit	Weight	Abbreviation	Description
0	1	STBY	standby
1	2	EN	enabled
2	4	RSEN	remote sense
3	8	LOCK	front panel locked
4	16	CC	constant current regulation, regulation status
5	32	CV	constant voltage regulation, regulation status
6	64	CR	constant resistance regulation, regulation status
7	128	CP	constant power regulation, regulation status

14.10.1.3. StatusRegQ¶

This command queries the Status Register. This read-only register holds the live (unlatched) operation status of the MagnaLOAD electronic load. Issuing a query does not clear the register. The register location and definitions are subject to change after any firmware release to accommodate new features. The Questionable Register is a subset of the status register and does not change between firmware updates. The present bit assignments are shown in the table below.

Index: 0x200D
Access: RO
Data Format: 32-bit Integer

Status Register 0

Bit	Name	Description
0	standby	output is in standby
1	live	output is active
2	solenoidStatus	aux power solenoid is open
3	nonhalt2	available
4	overCurrTrip	over current trip
5	overVoltTrip	over voltage trip
6	overPwrTrip	over power trip
7	remoteSenseLoss	remote sense voltage outside of acceptable bounds
8	underVoltTrip	under voltage trip
9	shutdown	target is creating a shutdown condition
10	linPwrLim	power across linear modules exceed ratings
11	resPwrLim	power across resistors exceed ratings
12	bootFailure	one or multiple target did not boot up
13	bootState	one or more targets are waiting to boot
14	phaseCurr	rated phase current exceeded
15	comm	communications are corrupted
16	overCurrProtect	terminal current exceeded product rating
17	overVoltProtect	terminal voltage exceeded product rating
18	tempRLin	linear module exceeded temperature
19	blownFuse	fuse is blown on the auxiliary power supply
20	interlock	interlock open
21	haltUserClear	available
22	maintenance	maintenance
23	tempDMod	diode modules exceeded temperature
24	incompatibleSysConfig	incompatible system configuration
25	stackOverflow	exceeded firmware stack
26	lineFault	line fault analog/digital inputs
27	tempRMod	resistor module exceeded temperature
28	belowRatedMinVolt	below minimum voltage rating(28)
29	outOfRegulation	out of regulation, unexpected currents measured
30	targetUpgrade	mainctrl upgrading other targets
31	haltSelfClear	available

Status Register 1

Bit	Name	Description
0	phaseLoss	one or more phase missing
1	blownFuseInput	input fuse blown on fuse/emi filter
2	fanLockedRotor	one or more fan’s rotor has locked
3	notUsed29	available
4	tempPwrMod	power processing module temperature fault
5	tempOutputMod	output filter module temperature fault
6	tempOutputCap	output capacitors temperature fault
7	tempTransformer	transformer exceeded temperature fault
8	notUsed26	available
9	notUsed27	available
10	notUsed28	available
11	notUsed1	available
12	notUsed2	available
13	notUsed3	available
14	notUsed4	available
15	notUsed5	available
16	invalidSysRating	invalid system rating
17	fwVersConflict	firmware version conflict
18	notUsed8	available
19	notUsed9	available
20	notUsed10	available
21	notUsed11	available
22	notUsed12	available
23	notUsed13	available
24	notUsed14	available
25	notUsed15	available
26	notUsed16	available
27	notUsed17	available
28	notUsed18	available
29	notUsed19	available
30	notUsed20	available
31	notUsed21	available

14.10.1.4. Input¶

This command enables or disables the MagnaLOAD electronic load input. The state of a disabled input is a high impedance condition.

Index: 0x2011
Access: RW
Data Format: Boolean
Index: 0x2012
Access: RO
Data Format: Boolean

14.10.2. Measurement Commands¶

14.10.2.1. MeasCurrQ¶

This query commands the MagnaLOAD electronic load to measure and return the average current through the DC terminals.

Index: 0x2101
Access: RO
Data Format: 32-bit Floating Point Number

14.10.2.2. MeasVoltQ¶

This query commands commands the MagnaLOAD electronic load to measure and return the average voltage at the DC terminals. If the remote sense function is used and engaged, this command returns the voltage measured at the sense terminals.

Index: 0x2102
Access: RO
Data Format: 32-bit Floating Point Number

14.10.2.3. MeasPwrQ¶

This query commands commands the MagnaLOAD electronic load to measure and return the average power at the DC terminals.

Index: 0x2103
Access: RO
Data Format: 32-bit Floating Point Number

14.10.2.4. MeasResQ¶

This query commands commands the MagnaLOAD electronic load to measure and return the average power at the DC terminals.

Index: 0x2104
Access: RO
Data Format: 32-bit Floating Point Number

14.10.3. Setpoint Commands¶

14.10.3.1. SetpointCurr¶

This command programs the current set-point that the MagnaLOAD electronic load will regulate to when operating in constant current mode.

Index: 0x2201
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2202
Access: RO
Data Format: 32-bit Floating Point Number

14.10.3.2. SetpointVolt¶

This command programs the voltage set-point, in volts, which the MagnaLOAD electronic load will regulate to when operating in constant voltage mode.

Index: 0x2203
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2204
Access: RO
Data Format: 32-bit Floating Point Number

14.10.3.3. SetpointPwr¶

This command programs the power set-point, in watts, which the MagnaLOAD electronic load will regulate to when operating in constant power mode.

Index: 0x2205
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2206
Access: RO
Data Format: 32-bit Floating Point Number

14.10.3.4. SetpointRes¶

This command programs the resistance set-point, in ohms, which the MagnaLOAD electronic load will regulate to when operating in constant resistance mode.

Index: 0x2207
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2208
Access: RO
Data Format: 32-bit Floating Point Number

14.10.4. Trip Commands¶

14.10.4.1. OverTripCurr¶

This command programs the over current trip (OCT) set-point. If the input current exceeds the over current trip set-point for multiple samples, the input is disconnected and an OCT fault is indicated.

Index: 0x2301
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2302
Access: RO
Data Format: 32-bit Floating Point Number

14.10.4.2. OverTripVolt¶

This command programs the over voltage trip (OVT) set-point. If the input voltage exceeds the over voltage trip set-point for multiple samples, the input is disconnected and an OVT fault is indicated.

Index: 0x2303
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2304
Access: RO
Data Format: 32-bit Floating Point Number

14.10.4.3. OverTripPwr¶

This command programs the over power trip (OPT) set-point. If the input power exceeds the over power trip set-point for multiple sample, the input is disconnected and an OPT fault is indicated.

Index: 0x2305
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2306
Access: RO
Data Format: 32-bit Floating Point Number

14.10.4.4. UnderTripVolt¶

This command programs the under voltage trip (UVT) set-point. If the input voltage falls below the under voltage trip set-point for multiple samples, the input is disconnected and an UVT fault is indicated.

Index: 0x2307
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2308
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5. Slew Commands¶

14.10.5.1. RiseRampCurr¶

This command sets the current slew rate for increasing current transitions while in constant current regulation. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x2401
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2402
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.2. RiseRampVolt¶

This command sets the voltage slew rate for increasing voltage transitions while in constant voltage regulation. The units for voltage slew rate are volts per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x2403
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2404
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.3. RiseRampPwr¶

This command sets the power slew rate for increasing power transitions while in constant power regulation. The units for power slew rate are watts per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x2405
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2406
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.4. RiseRampRes¶

This command sets the resistance slew rate for increasing resistance transitions while in constant resistance regulation. The units for resistance slew rate are ohms per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x2407
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2408
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.5. FallRampCurr¶

This command sets the current slew rate for decreasing current transitions while in constant current regulation. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x2409
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x240A
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.6. FallRampVolt¶

This command sets the voltage slew rate for decreasing voltage transitions while in constant voltage regulation. The units for voltage slew rate are volts per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x240B
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x240C
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.7. FallRampPwr¶

This command sets the power slew rate for decreasing power transitions while in constant power regulation. The units for power slew rate are watts per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x240D
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x240E
Access: RO
Data Format: 32-bit Floating Point Number

14.10.5.8. FallRampRes¶

This command sets the resistance slew rate for decreasing resistance transitions while in constant resistance regulation. The units for resistance slew rate are ohms per millisecond. MAXimum sets the slew to the fastest possible rate. MINimum sets the slew to the slowest rate. Slew rates less than the minimum value are set to MINimum. Slew rate settings less than the minimum value are set to MINimum. Slew rate settings greater than the maximum value are set to MAXimum.

Index: 0x240F
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2410
Access: RO
Data Format: 32-bit Floating Point Number

14.10.6. Control Commands¶

14.10.6.1. ControlMode¶

This command configures the MagnaLOAD electronic load’s control mode. Control Modes provides more information about the various options.

Index: 0x2503
Access: RW
Data Format: 16-bit Integer
Index: 0x2504
Access: RO
Data Format: 16-bit Integer

14.10.7. Function Generator Commands¶

14.10.7.1. FuncType¶

This command selects the desired function for the integrated function generator, which is active when the product’s set point source is set to function generator.

Index: 0x2601
Access: RW
Data Format: 16-bit Integer
Index: 0x2602
Access: RO
Data Format: 16-bit Integer

14.10.7.2. FuncSinAmpl¶

This command sets the amplitude (Adc) for the sinusoid function when the set point source is set to 1 (function generator) and the function type is set to 0 (sinusoid).

Index: 0x2603
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2604
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.3. FuncSinOff¶

This command sets the DC offset from zero (Adc) for the sinusoid function midline when the set point source is set to 1 (function generator) and the function type is set to 0 (sinusoid).

Index: 0x2605
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2606
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.4. FuncSinPrd¶

This command sets the period (milliseconds) for the sinusoid function when the set point source is set to 1 (function generator) and the function type is set to 0 (sinusoid). The sinusoid’s period is the length of one full cycle.

Index: 0x2607
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2608
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.5. FuncSquLoLevel¶

This command sets the low level amplitude for the square function when the set point source is set to 1 (function generator) and the function type is set to 1 (square).

Index: 0x2609
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x260A
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.6. FuncSquHiLevel¶

This command sets the high level amplitude for the square function when the set point source is set to 1 (function generator) and the function type is set to 1 (square).

Index: 0x260B
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x260C
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.7. FuncSquLoPrd¶

This command sets the period/duration (milliseconds) that the square function remains at the low level amplituide when the set point source is set to 1 (function generator) and the function type is set to 1 (square).

Index: 0x260D
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x260E
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.8. FuncSquHiPrd¶

This command sets the period/duration (milliseconds) that the square function remains at the low level amplituide when the set point source is set to 1 (function generator) and the function type is set to 1 (square).

Index: 0x260F
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2610
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.9. FuncStepLoLevel¶

This command sets the low level amplitude for the step function when the set point source is set to 1 (function generator) and the function type is set to 2 (step).

Index: 0x2611
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2612
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.10. FuncStepHiLevel¶

This command sets the high level amplitude for the step function when the set point source is set to 1 (function generator) and the function type is set to 2 (step).

Index: 0x2613
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2614
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.11. FuncRampLoLevel¶

This command sets the low level amplitude for the ramp function when the set point source is set to 1 (function generator) and the function type is set to 3 (ramp).

Index: 0x2615
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2616
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.12. FuncRampHiLevel¶

This command sets the high level amplitude for the ramp function when the set point source is set to 1 (function generator) and the function type is set to 3 (ramp).

Index: 0x2617
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x2618
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.13. FuncRampRisePrd¶

This command sets the period/duration (milliseconds) for the ramp function to transition from the low level amplitude to the high level amplitude when the set point source is set to 1 (function generator) and the function type is set to 3 (ramp).

Index: 0x2619
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x261A
Access: RO
Data Format: 32-bit Floating Point Number

14.10.7.14. FuncRampFallPrd¶

This command sets the period/duration (milliseconds) for the ramp function to transition from the high level amplitude to the low level amplitude when the set point source is set to 1 (function generator) and the function type is set to 3 (ramp).

Index: 0x261B
Access: RW
Data Format: 32-bit Floating Point Number
Index: 0x261C
Access: RO
Data Format: 32-bit Floating Point Number

14.10.8. Configuration Commands¶

14.10.8.1. FactoryRestore¶

This command performs a factory restore to default EPROM values. Both Soft Restore and Hard Restore are available through command parameters.

Index: 0x2701
Access: RW
Data Format: 16-bit Integer

14.10.8.2. Lock¶

This command configures the MagnaLOAD electronic load’s lock state. While locked, the stop button is the only functional button on the front panel. See Lock for more details on how lock works and how behaves relative to other locking inputs (front panel and digital input).

Index: 0x2703
Access: RW
Data Format: Boolean
Index: 0x2702
Access: RO
Data Format: Boolean

14.10.8.3. SenseMode¶

This command configures where the MagnaLOAD electronic load senses voltage. The sense location also effects how power and resistance are calculated. Local sensing monitors the directly across the output terminals. Remote sensing, as described in Remote Sense Connection, measures across the terminal JS2. This external connection can be used to improve regulation at the point of load, as is needed for example, in compensating voltage drops caused by wire resistance.

Index: 0x2706
Access: RW
Data Format: 16-bit Integer
Index: 0x2707
Access: RO
Data Format: 16-bit Integer

14.10.8.4. CommProt¶

This command changes the command protocol of the MagnaLOAD electronic load.

Index: 0x2708
Access: RW
Data Format: 16-bit Integer
Index: 0x2709
Access: RO
Data Format: 16-bit Integer

14.10.8.5. SetSource¶

The command selects and routes different set points sources to the digital controller. Operation of this feature is described in Set Point Source. By default, the source is set to local (value 0), where set points originating from the front panel or communication interfaces are routed to the ALx Series digital control. When the source is set to function generator (value 1), set points are generated internally, by a periodic function generator block. When external analog input (value 3) is set, the voltage(s) applied to the rear connector are converted into set points.

Index: 0x270A
Access: RW
Data Format: 16-bit Integer
Index: 0x270B
Access: RO
Data Format: 16-bit Integer

14.10.8.6. MagnaLinkMode¶

This command changes the MagnaLINK mode to allow for standalone or master-slave configurations.

Index: 0x270C
Access: RW
Data Format: 16-bit Integer
Index: 0x270D
Access: RO
Data Format: 16-bit Integer

14.10.8.7. MagnaLinkReinit¶

This command should be used to reinitialize system ratings when a slave is added or removed from a master-slave configuration.

Index: 0x270E
Access: RW
Data Format: 16-bit Integer

14.10.8.8. CoolingMode¶

This command configures the MagnaLOAD electronic load’s cooling mode. In Automatic Cooling mode (value 0), the cooling output is regulated automatically based on internal operating conditions. In Maximum Cooling mode (value 1), the cooling output is forced on at full capacity. When queried, the command returns two comma-separated values: the configured cooling mode followed by the current solenoid state (0 = OFF, 1 = ON) on water-cooled units, or 0 on air-cooled units.

Index: 0x270F
Access: RW
Data Format: 16-bit Integer
Index: 0x2710
Access: RO
Data Format: 16-bit Integer