1756-M02AS | Allen-Bradley ControlLogix 2 Axis Analog/SSI Servo Module

Description 

The Allen-Bradley 1756-M02AS is a ControlLogix Integrated Motion module. This module is used with Analog Servo interface drives with SSI feedback. It has two (2) axes per module and supports Position loop, Velocity loop for Torque; Position loop and for Velocity or Hydraulic. It has a gain resolution of 32-bit floating point with absolute position range 4,294,967,296 transducer counts and with user selectable rates of 500 Hertz, 666.7 Hertz, 1 Kilohertz, 2 Kilohertz, and 4 Kilohertz . This module directly installs to a ControlLogix chassis and it has a current draw of 700 milliamperes @ 5.1 Volts DC and 2.5 milliamperes @ 24 Volts DC.

Technical Specifications 

Information About 1756-M02AS

The Allen-Bradley 1756-M02AS is a synchronous serial interface, or SSI, servo module. It is an analog servo interface module that has 2 axes available. Up to 32 axes of the 1756-M02AS module can be installed in a controller. This module has been optimized for control of drives or actuators that require +/-10V velocity or torque reference input. The 1756-M02AS module has an SSI position feedback output and is a cost-effective option for open-loop or closed-loop motion control of devices that support an analog motion interface. This module is compatible with a wide range of quadrature output rotary and linear transducers. SSI devices available are rotary absolute and incremental encoders, linear absolute and incremental encoders, linear laser distance, linear absolute glass scales, and linear magnetostrictive. You can use either the cage clamp 1756-TBCH or spring clamp 1756-TBS6H RTB for this module. It has two types of servo loops: torque and velocity/hydraulic. The torque has a PID with velocity feedforward position loop and its velocity loop is PI with Accel feedforward (nested) and with directional scaling and friction compensation. The velocity has a position loop of PID with velocity feedforward and accel feedforward with directional scaling and friction compensation. The velocity loop is not applicable, as it is handled by the drive or valve. The 1756-M02AS module has a gain resolution of 32-bit floating point and an absolute position range of 4,294,967,296 transducer counts. It has a selectable rate of 500Hz, 666.7Hz, 1kHz, 2kHz, and 4kHz and an update period of 250µsec, 500µsec, 1msec, 1.5msec, and 2msec. Its resolution ranges from 8 to 31 bits and it has an isolated 5V differential electrical interface (RS-422 signal). It also has an input impedance of 215 ohm differential and an output load of 100 ohm minimum. It has a clock frequency of 205kHz or 625kHz and the transducer can either be binary or gray code. It is an optically isolated, current sinking module. The 1756-M02AS module has a nominal input voltage of 24V DC, an off-state maximum voltage of 8.5V DC, and an on-state voltage that ranges from 17V DC to 26.4V DC. It has a current draw of 700 mA and 2.5 mA at 5.1V DC and 24V DC respectively. It also has a power dissipation of 5.5 W, a thermal dissipation of 18.77 BTU/hr, and an isolation voltage of 30V that is continuous from user to system.

The Allen-Bradley 1756-M02AS is a Motion interface module. This module is specifically an analog motion module, used for open loop and closed loop motion applications. This module comes with built-in support for 2 motion axes - however, additional modules may be installed if needed, to provide up to 32 axes of motion axes per ControlLogix processor.

The 1756-M02AS supports Torque Position and Velocity loop. With position loop, Proportional + Integral + Derivative (PID) with velocity feed-forwards is utilized while for Velocity loop. Proportional + Integral (PI) with accel feed-forwards is used including directional scaling and friction compensation capability. This module may also control the Position loop of velocity or hydraulic drive. With this, a combined function of Position and Velocity is used where PID with velocity feed-forwards and acceleration feed-forwards with directional scaling and friction compensation is utilized.

The 1756-M02AS has a gain resolution of 32-bit floating point value with absolute position range of 232 (4,294,967,296) transducer counts with user configurable rate of 500 Hertz, 666.7 Hertz, 1 Kilohertz, 2 Kilohertz, and 4 Kilohertz. It is a single slot module that directly mounts to any available slot of the ControlLogix chassis. Compatible 1756 chassis for this module include the 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17. It requires use of a 1756-TBCH or 1756-TBS6H Removable Terminal Block (RTB) for wiring of signals. It also supports the ControlLogix standard power supply (1756-PA72/C, 1756-PA75/B, 1756-PB72/C, 1756-PB75/B, 1756-PC75/B, 1756-PH75/B) and ControlLogix redundant Power supply (1756-PA75R, 1756-PB75R, 1756-PSCA2).

The 1756-M02AS’s input type is Synchronous Serial Interface (SSI) input with a resolution of 8-31 bits. The input interface of this module has a rated isolation of Isolated 5V differential (RS-422 signal) with a clock frequency of 208 Kilohertz or 625 Kilohertz. It uses a Binary or Gray code transducer. It also has a Registration input that supports Current sinking circuit with optical isolation. Similarly, other input types for this module also support current sinking configuration with optical isolation as well.

Manufacturer information

Allen-Bradley, a brand of Rockwell Automation, specializes in manufacturing industrial automation equipment. The product range includes programmable logic controllers (PLCs), motion control systems, safety devices, motor control equipment, automation software, and HMI panels. Allen-Bradley products are known for their reliability and integration with other systems.