SLx Series
Programmable DC Power Supply
Building on over 40 years of power supply innovation and with over 26,500+ different model configurations, the SLx Series is Magna-Power’s most versatile programmable DC power supply series ever created. The SLx Series offers models at 6 different power levels, with highly granular range of voltages and currents. With industry-leading power density, rugged current-fed power processing, and the state-of-the-art MagnaLINK™ distributed DSP digital control architecture, the SLx Series meets the long-term DC power requirements of research & development, industrial automation, and process control applications.
Key Features
- Voltage, current, and power control
- Rugged current-fed power processing
- 16-bit precision with single bit control
- SCPI and Modbus command sets
- Programmable protection features
- Interlock and hardware emergency stop
- Slew rate control
- Continuous full power operation up to 50°C ambient
- Configurable analog-digital 26-pin I/O port
- Digital-hybrid MagnaLINK™ master-slaving
- Local, remote, and leadless voltage sensing
- USB (front and rear) and RS485 interfaces standard
- CAN, EtherCAT, EtherNet/IP, LXI TCP/IP Ethernet, ModbusTCP, and PROFINET fully integrated communications options available
- MagnaCTRL software platform included
- Made in the USA
Build-Time: 10-12 Weeks
MagnaLINK™ Distributred Digital Control
Magna-Power developed its MagnaLINK™ digital control platform from the ground up to utilize an array of four Texas Instruments DSPs distributed across various internal assemblies. High-speed board-to-board communications is achieved between DSPs utilizing an internally developed low-level communication protocol. A custom bootloader ensures long-term support with multi-target firmware updates and synchronization. New capabilities are achieved with the MagnaLINK digital architecture, some of which include: slew rate control, gain modification, 16-bit precision, 100 ppm stability, user-defined sequencing and function generation, and digital hybrid master-slaving.
Made in the USA, Available Worldwide
MagnaDC programmable DC power supplies are designed and manufactured at Magna-Power’s 73,500 sq-ft vertically integrated USA manufacturing facility in Flemington, New Jersey. From raw materials to the completed product, Magna-Power has insourced nearly the entire production process to maintain complete control of quality, cost, and build-time. Heat-sinks and various metal assemblies are machined through both automated CNC and EDM. Sheet metal is cut, punched, sanded, bent, and powder coated in-house. Magnetics are wound-to-order from validated designs based on a model’s voltage and current. A full surface mount technology (SMT) with multiple stages of 3D automated optical inspection ensures high-quality printed circuit board assemblies. Finally, after assembly, products undergo comprehensive test and calibration, followed by an extended burn-in period.
Products are sold directly from the factory and through distribution, with a service network around the world.
Reliable Current-Fed Power Processing
All MagnaDC programmable DC power supplies utilize high-frequency IGBT- and MOSFET-based power processing in current-fed topology. This topology adds an additional stage over the conventional voltage-fed topology for enhanced control and system protection, ensuring that even under a fault condition, the power supply will self-protect. Due to the self-protecting characteristics of this topology, the possibility of fast rising current spikes and magnetic core saturation is eliminated. This topology coupled with state-of-the-art Silicon Carbide (SiC) power semiconductors enables the SLx Series to deliver class-leading power density, reliability and efficiency with continuous full-power operation up to 50°C ambient.
Intuitive, Bright, Long-Lasting Front Panel Interface
Prioritizing brightness and reliability, the SLx Series features of a hybrid display with bright green segments for voltage and current output and a multi-line display for power measurement, settings configuration, and status messages. A black-anodized machined aluminum control knob enables precise dialing of control set points, while a 10-digit key and arrow buttons provide digital set point inputs with 16-bit precision. In addition, a dedicated Lock button enables users to lock out the front panel to prevent unwanted changes from the front panel. Easily connect a computer to the SLx Series without going behind it by using the front panel USB port; a rear-mounted USB port is also provided.
Communication Interfaces for Industrial Control
SLx Series power supplies come standard with Dual USB (front and back) and RS485. Options are available to provide seamless fully integrated communication for either traditional TCP/IP network control (SCPI or Modbus) or through direct control over industrial communication interfaces (Modbus). Magna-Power has taken significant measures to ensure comprehensive command-set support and documentation across the following optional interfaces:
- CANopen (+CAN)
- EtherCAT (+ECAT)
- EtherNet/IP (+EIP)
- LXI TCP/IP Ethernet (+LXI)
- Modbus-TCP (+MTCP)
- PROFINET (+PROF)
Standard Safety Features with Emergency Stop
The SLx Series features a soft-start circuit to eliminate large peak in-rush currents from the AC mains, ensuring AC current draw never exceeds the current draw at full load. The SLx Series programmable DC power supplies have extensive safety and diagnostic functions, including:
- AC Phase Loss
- Over Voltage Trip (Programmable)
- Over Current Trip (Programmable)
- Over Power Trip (Programmable)
- Cleared Fuse
- Over Voltage on Program Line Input
- Over Temperature on Internal Heatsink or Output Capacitors
- Internal Communications Fault
- Interlock and Emergency Stop Fault
When a fault is detected, the power supply immediately shuts down power processing circuit, utilizing the immediate one-shot trip (OSHT) zone event for inverter PWM channels. Users can easily identify faults using the Status message display or by SCPI/Modbus commands.
Finally, both interlock and emergency stop features are included as standard. The interlock feature provides a 5V interlock input, which when coupled with the provided 5V reference signal, allows for a dry contact to easily trigger a latching interlock fault, while maintaining control power. A separate emergency stop feature bypasses all logic and processors to provide a hardware-only path to easily interrupt AC power to the SLx Series power supply with a 24V signal, providing a full hardware shutdown.
Plug & Play Master-Slaving
The SLx Series includes Magna-Power’s next-generation digital hybrid master-slaving interface via dual digital MagnaLINK communication ports. With support up to 12 units in a master-slave set, users can easily expand their current capability by adding more units in parallel. A secondary current sense connection is provided, which provides real-time analog current feedback to the master, enabling reliable, high-accuracy measurement aggregation to a single display.
Target Diagnostics for Easy Field Servicing
The SLx Series introduces Magna-Power’s Target Diagnostics feature, mapping the status LEDs for every major assembly to a rear mounted LED matrix. This LED matrix provides the statuses of each internal assembly, easily allowing users or support teams to understand faults or configuration issues, while keeping products mounted and covers on. The Target Diagnostics feature coupled with MagnaCTRL’s EPROM editor offers a robust suite of remote support tools to effectively reduce downtime.
Software Integration with Ease
With standard support for Standard Commands for Programmable Instrumentation (SCPI) and Modbus, SLx Series power supplies provide an easy-to-use API with well-documented commands in readable text. Over 60 commands allow programmatic access to product registers, starting and stopping the product, control of voltage, current and power, slew rate control, high-accuracy measurement queries, and product configuration. Simple scripting or complex software can be achieved, with extensive documentation and examples provided by Magna-Power.
import serial
magnaPower = serial.Serial(port='COM4', baudrate=19200)
magnaPower.write('*IDN?\n'.encode())
print magna_power.readline()
magnaPower.write('VOLT 0\n'.encode())
magnaPower.write('CURR 0\n'.encode())
magnaPower.write('OUTP:START\n'.encode())
magnaPower.write('VOLT 270\n'.encode())
currSetPoints = [50, 100, 150, 250]
for currSetPoint in currSetPoints:
print 'Setting Current to %s A' % currSetPoint
magnaPower.write('CURR {0}\n'.format(currSetPoint).encode())
magnaPower.write('MEAS:VOLT?\n'.encode())
print magnaPower.readline()
time.sleep(20)
magnaPower.write('OUTP:STOP\n'.encode())
magnaPower.close()
magna_power = serial('COM4', 'BaudRate', 19200);
fopen(magnaPower);
fprintf(magnaPower,'*IDN?');
idn = fscanf(magnaPower);
fprintf(magnaPower,'VOLT 0');
fprintf(magnaPower,'CURR 0');
fprintf(magnaPower,'OUTP:START');
fprintf(magnaPower,'VOLT 270');
for currSetPoint in [50, 100, 150, 250]
display('Setting Current to '+currSetPoint+' A');
fprintf(magnaPower, 'CURR '+currSetPoint);
fprintf(magnaPower,'MEAS:VOLT?');
display(fscanf(magnaPower));
pause(20);
end
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <windows.h>
int main()
{
printf("Opening connection.\n");
uint8_t recvBuffer[sizeof(uint8_t) * 256];
memset(recvBuffer, 0, 256);
// Choose the serial port name.
// COM ports higher than COM9 need the \\.\ prefix, which is written as
// "\\\\.\\" in C because we need to escape the backslashes.
const char* device = "\\\\.\\COM4";
// Choose the baud rate (bits per second).
uint32_t baud_rate = 9600;
HANDLE port = open_serial_port(device, baud_rate);
if (port == INVALID_HANDLE_VALUE) { return 1; }
char* scpiCmd = (char*)"*IDN?\n";
size_t cmdLen = strlen(scpiCmd);
int result = write_port(port, (uint8_t*)scpiCmd, cmdLen);
if (result < 0)
return -1;
result = read_port(port, recvBuffer, 256);
printf("Sent: %s\nReceived: %s\n", scpiCmd, recvBuffer);
scpiCmd = (char*)"VOLT 0\n";
cmdLen = strlen(scpiCmd);
result = write_port(port, (uint8_t*)scpiCmd, cmdLen);
if (result < 0)
return -1;
scpiCmd = (char*)"CURR 0\n";
cmdLen = strlen(scpiCmd);
result = write_port(port, (uint8_t*)scpiCmd, cmdLen);
if (result < 0)
return -1;
scpiCmd = (char*)"OUTP:START\n";
cmdLen = strlen(scpiCmd);
result = write_port(port, (uint8_t*)scpiCmd, cmdLen);
if (result < 0)
return -1;
scpiCmd = (char*)"VOLT 270\n";
cmdLen = strlen(scpiCmd);
result = write_port(port, (uint8_t*)scpiCmd, cmdLen);
if (result < 0)
return -1;
char setPoints[4][5] = {"50", "100", "150", "200"};
char setPointBuffer[40];
scpiCmd = (char*)"MEAS:VOLT?\n";
for (int i = 0; i < 4; i++)
{
sprintf(setPointBuffer, "CURR %s\n", setPoints[i]);
printf("Setting current to %s A\n", setPoints[i]);
cmdLen = strlen(setPointBuffer);
result = write_port(port, (uint8_t*)setPointBuffer, cmdLen);
if (result < 0)
return -1;
memset(recvBuffer, 0, 256);
result = read_port(port, recvBuffer, 256);
printf("Received: %s\n", recvBuffer);
Sleep(20000); // 20000ms = 20s
}
scpiCmd = (char*)"OUTP:STOP\n";
cmdLen = strlen(scpiCmd);
result = write_port(port, (uint8_t*)scpiCmd, cmdLen);
if (result < 0)
return -1;
CloseHandle(port);
printf("Connection closed.\n");
return 0;
}
using System;
using System.IO.Ports;
using System.Threading;
namespace SerialCommunicationInCSharp
{
public class Program
{
static bool _continue;
static SerialPort serialPort;
public static void Main(string[] args)
{
Thread readThread = new Thread(Read);
Console.WriteLine("Opening connection.");
// Create a new SerialPort object with default settings.
serialPort = new SerialPort("COM4", 19200, Parity.None, 8, StopBits.One);
// Set the read/write timeouts
serialPort.ReadTimeout = 500;
serialPort.WriteTimeout = 500;
serialPort.Open();
_continue = true;
readThread.Start();
Console.WriteLine("Sending: *IDN?");
serialPort.WriteLine("*IDN?");
serialPort.WriteLine("VOLT 0");
serialPort.WriteLine("CURR 0");
serialPort.WriteLine("OUTP:START");
serialPort.WriteLine("VOLT 270");
string[] currSetPoints = { "50", "100", "150", "250" };
ß
for(int i = 0; i < currSetPoints.Length; i++)
{
serialPort.WriteLine(String.Format("'CURR {0}", currSetPoints[i]));
serialPort.WriteLine("MEAS:VOLT?");
Thread.Sleep(20000);
}
serialPort.WriteLine("OUTP:STOP");
Console.WriteLine("Closing connection.");
_continue = false;
serialPort.Close();
}
public static void Read()
{
while (_continue)
{
try
{
string message = serialPort.ReadLine();
Console.WriteLine("Received: " + message);
}
catch (TimeoutException) { }
}
}
}
}
Configurable User I/O for Analog & Digital Controls
All SLx Series power supplies come standard with a 26-pin D-Sub connector designated as the External User I/O. This connector provides:
- 8 Digital Outputs (5V logic)
- 4 Digital Inputs (5V logic)
- 4 Analog Outputs (0-10V logic)
- 4 Analog Inputs (0-10V logic)
The External User I/O is isolated from the output terminals and referenced to earth ground. The connector’s pins are user configurable, allowing users to select the functions needed in their application, while providing future capability for new features. Use the digital outputs to integrate the power supply with, for example, external enable signals or digital fault monitoring logic, or monitor voltage-current using the analog 0-10V outputs. A dedicated high-speed analog input is also provided, sampled at 2 kHz for near real-time control.
Included MagnaCTRL Software
Magna-Power’s brand new MagnaCTRL Software comes standard with all SLx Series products, providing a modern, feature-rich, multi-product control platform. MagnaCTRL provides various Panels to allow for computer-based control, monitoring, sequencing, and firmware update capabilities.
Model Ordering Guide
For both ordering and production, SLx Series models are uniquely defined by several key characteristics, as defined by the following diagram:
SLx Series Models
There are 171 different models in the SLx Series spanning power levels: 1.5 kW, 2.6 kW, 4 kW, 6 kW, 8 kW, 10 kW. To determine the appropriate model:
- Select the desired Max Voltage (Vdc) from the left-most column.
- Select the desired Max Current (Adc) from the same row that contains your desired Max Voltage.
- Construct your model number according to the model ordering guide.
1.5 kW | 2.6 kW | 4 kW | 6 kW | 8 kW | 10 kW | |||
---|---|---|---|---|---|---|---|---|
Max Voltage (Vdc) | Max Current (Adc) | Ripple (mVrms) | Efficiency | |||||
5 | 250 | 500 | 600 | N/A | N/A | N/A | 30 |
84% |
10 | 150 | 250 | 400 | 600 | N/A | N/A | 30 | 89% |
16 | 93 | 162 | 250 | 375 | 500 | 600 | 40 | 89% |
20 | 75 | 130 | 200 | 250 | 400 | 500 | 40 | 90% |
25 | 60 | 104 | 160 | 240 | 320 | 400 | 50 | 91% |
32 | 46 | 81 | 125 | 186 | 250 | 310 | 60 | 91% |
40 | 37 | 65 | 100 | 150 | 200 | 250 | 80 | 91% |
50 | 30 | 52 | 80 | 120 | 160 | 200 | 70 | 92% |
60 | 25 | 43 | 66 | 100 | 133 | 166 | 100 | 93% |
80 | 18 | 32 | 50 | 75 | 100 | 125 | 120 | 93% |
100 | 15 | 26 | 40 | 60 | 80 | 100 | 120 | 93% |
125 | 12 | 20 | 32 | 48 | 64 | 80 | 110 | 93% |
160 | 9 | 16 | 25 | 36 | 50 | 60 | 110 | 93% |
200 | 7.5 | 13 | 20 | 30 | 40 | 50 | 110 | 94% |
250 | 6 | 10.4 | 16 | 24 | 32 | 40 | 110 | 94% |
300 | 5 | 8.6 | 13.2 | 20 | 26.4 | 33.3 | 160 | 94% |
375 | 4 | 6.9 | 10.4 | 16 | 21.3 | 26.5 | 160 | 94% |
400 | 3.7 | 6.5 | 10 | 15 | 20 | 25 | 170 | 95% |
500 | 3 | 5.2 | 8 | 12 | 16 | 20 | 250 | 95% |
600 | 2.5 | 4.3 | 6.4 | 10 | 13.3 | 16.5 | 250 | 95% |
800 | 1.8 | 3.2 | 5 | 7.5 | 10 | 12.5 | 350 | 95% |
1000 | 1.5 | 2.6 | 4 | 6 | 8 | 10 | 400 | 95% |
1250 | 1.2 | 2 | 3.2 | 4.8 | 6.4 | 8 | 700 | 95% |
1500 | 1 | 1.7 | 2.6 | 4 | 5.3 | 6.6 | 1000 | 95% |
2000 | 0.75 | 1.3 | 2 | 3 | 4 | 5 | 1000 | 95% |
3000 | 0.5 | 0.86 | 1.3 | 2 | 2.6 | 3.3 | 1000 | 95% |
4000 | 0.37 | 0.65 | 1 | 1.5 | 2 | 2.5 | 1000 | 95% |
6000 | 0.25 | 0.43 | 0.66 | 1 | 1.33 | 1.66 | 1000 | 95% |
8000 | 0.18 | 0.32 | 0.5 | 0.75 | 1 | 1.25 | 1000 | 95% |
10000 | 0.15 | 0.26 | 0.4 | 0.6 | 0.8 | 1 | 1000 | 95% |
Specifications
The following specifications are subject to change without notice. Unless otherwise noted, all specifications measured at the product's maximum ratings.
Specification | Value |
---|---|
Input Voltages Available
Refer to models table for AC input voltage availability by power level. AC Input voltage specified at time of order and cannot be modified |
UI, 100-240 Vac, 1-phase UI2, 208-240 Vac, 1-phase 208 Vac, 3-phase 240 Vac, 3-phase 380/400 Vac, 3-phase 415 Vac, 3-phase 440 Vac, 3-phase 480 Vac 3-phase |
Input Voltage Tolerance
|
± 10% |
Input Voltage Frequency
|
50-400 Hz |
Power Factor
Measured at max power |
> 0.99, 1-phase UI and UI2 AC inputs > 0.92, 3-phase AC inputs |
Input Isolation
Measured line-to-ground |
± 2000 Vdc |
Specification | Value |
---|---|
Voltage Ripple
|
Model specific. Refer to models table. |
Line Regulation
|
Voltage control: ± 0.04% of rated voltage Current control: ± 0.03% of rated current Power control: ± 0.05% of rated power |
Load Regulation
|
Voltage control: ± 0.02% of rated voltage Current control: ± 0.06% of rated current Power control: ± 0.08% of rated power |
Stability
FWHM, measured at 25ºC over 8 hrs after 30 min warm-up |
Voltage control: ± 0.005% of rated voltage Current control: ± 0.075% of rated current |
Temperature Coefficient
|
Voltage control: 0.01%/ºC of rated voltage Current control: 0.04%/ºC of rated current Power control: 0.04%/ºC of rated power |
Efficiency
|
Up to 95%. Model specific. Refer to Models table. |
Slew Rate, Voltage
Standard models, programmable |
Minimum (Slowest): Rated voltage x 2-15 [V/ms] Maximum (Fastest): Rated voltage x 0.006 [V/ms] |
Slew Rate, Current
Standard models, programmable |
Minimum (Slowest): Rated current x 2-15 [A/ms] Maximum (Fastest): Rated current x 0.008 [A/ms] |
Slew Rate, Power
Standard models, programmable |
Minimum (Slowest): Rated power x 2-15 [W/ms] Maximum (Fastest): Rated power x 0.004 [W/ms] |
Output Isolation
Measured output-to-ground |
± 2000 Vdc |
Specification | Value |
---|---|
Resolution, Digital Programming
Front panel or communication interfaces |
16-bit, 0.00153% of rated voltage, current or power |
Accuracy, Digital Programming
Output value to set point value, programmed via front panel or communication interfaces |
Voltage: ± 0.06% of rated voltage Current: ± 0.06% of rated current Power: ± 0.10% of rated power |
Accuracy, Digital Measurement
Output value to returned value, via front panel display or communication interfaces |
Voltage: ± 0.08% of rated voltage Current: ± 0.08% of rated current Power: ± 0.10% of rated power |
Resolution, Analog Programming
0-10 V analog input |
12-bit, 0.025% of rated voltage, current or power |
Accuracy, Analog Programming
Output value to set point value, programmed via analog input |
Voltage: ± 0.12% of rated voltage Current: ± 0.08% of rated current Power: ± 0.10% of rated power |
Accuracy, Analog Programming, High Speed Input
Output value to set point value, programmed via the high-speed analog input |
Voltage: ± 0.80% of rated voltage Current: ± 0.80% of rated current Power: ± 1.20% of rated power |
Accuracy, Analog Measurement
Output value to returned value, via analog output |
Voltage: ± 0.08% of rated voltage Current: ± 0.08% of rated current Power: ± 0.10% of rated power |
Analog I/O
3 configurable standard analog inputs, 1 configurable high-speed analog input, reference signal provided |
High-Speed Input Sampling Rate: 2 kHz Programming Voltage: 0-10 V Monitoring Voltage: 0-10 V, 3 mA capacity Monitoring Impedance: 0.005 Ω Reference Voltage: 10 V, 20 mA capacity |
Specification | Value |
---|---|
Front Panel Programming
|
Machined aluminum rotary knob with encoder, keypad, and up-down arrow for single bit control |
Communication Interfaces
Standard |
USB Host (Front): Type B USB Host (Rear): Type B RS485 (Rear): RJ-45 MagnaLINK™: RJ-25 x 2 |
External User I/O Port
Standard |
26-pin D-sub DB-26, female Referenced to ground; isolated from the DC output See User Manual for pin layout |
Communication Interfaces
Optional |
CANopen (+CAN): DB-9 EtherCAT (+ECAT): RJ-45 x 2 EtherNet/IP (+EIP): RJ-45 x 2 LXI TCP/IP Ethernet (+LXI): RJ-45 ModbusTCP (+MTCP): RJ-45 x 2 PROFINET (+PROF): RJ-45 x 2 |
Specification | Value |
---|---|
Size
All models |
1U 1.75” H x 19” W x 24” D (4.4 x 48.3 x 61.0 cm) |
Weight
|
1.5 kW models: 32 lbs (14.52 kg) 2.6 kW models: 34 lbs (15.42 kg) 4 kW models: 35 lbs (15.88 kg) 6 kW models: 35 lbs (15.88 kg) 8 kW models: 36 lbs (16.33 kg) 10 kW models: 36 lbs (16.33 kg) |
Racking Standard
|
EIA-310 |
Rear Support Rails
|
Included |
Specification | Value |
---|---|
Ambient Operating Temperature
|
0°C to 50°C |
Storage Temperature
|
-35°C to +85°C |
Humidity
|
Relative humidity up to 95% non-condensing |
Air Flow
|
Side air inlet, rear exhaust |
Specification | Value |
---|---|
EMC
|
Complies with 2014/30/EU (EMC Directive) CISPR 22 / EN 55022 Class A |
Safety
|
Complies with EN61010-1 and 2014/35/EU (Low Voltage Directive) |
CE Mark
|
Yes |
RoHS Compliant
|
Yes |
REACH Compliant
|
Yes |
Dimensional Diagrams
The following are vectorized diagrams for the SLx Series. Refer to the Downloads section for downloadable drawings.
Options and Accessories
The following are options and accessories developed specifically for Magna-Power's SLx Series
Accessories
External accessories and integration services are available for Magna-Power products
DC Power Cables
DC power cables with wide range voltage ratings, current ratings, and termination options, made-to-order by Magna-Power
Rack Enclosures and Integration
Various size rack enclosures, including 12U, 24U, 30U, 36U, 30Ux2 and 36Ux2, with casters, fans and product integration.
Additional Accessories
Integrated Options
Standard integrated options are available for Magna-Power products, allowing the product's performance and communication interfaces to be tailors to the specific application.
CANopen
Option Code: +CAN
Availability:
CANopen communication protocol and dual RJ-45 interface enabling CAN bus communications, popular within automotive applications
EtherCAT
Option Code: +ECAT
Availability:
EtherCAT communication protocol and dual RJ-45 interface for high-performance communication in factory automation, motion control, and robotics
EtherNet/IP
Option Code: +EIP
Availability:
EtherNet/IP communication protocol and dual RJ-45 interface with EIS profile for industrial automation, commonly used in Allen Bradley, Schneider Electric, and Omron PLCs
LXI TCP/IP Ethernet
Option Code: +LXI
Availability:
TCP/IP Ethernet communication protocol and single RJ-45 interface, certified to the LXI Class C standard, for socket communications using conventional computer networks
Modbus-TCP
Option Code: +MTCP
Availability:
Modbus-TCP communication protocol and dual RJ-45 interface with full command set support as Modbus commands
PROFINET
Option Code: +PROF
Availability:
PROFINET communication protocol and dual RJ-45 interface for industrial automation, commonly used in Siemens PLCs
Ruggedized
Option Code: +RUG
Availability:
Internal product ruggedization, which has been independently tested to comply with select MIL-STD-810G and RTCA DO-160 shock and vibration specifications.
Downloads
The following downloads are for the SLx Series: