SSI Servo Module
21
Publication
1756-IN595A-EN-P - March 2004
1756-M02AS Specifications
Number of axes
2 axes maximum
Servo loop
Type
External Drive = Torque
External Drive = Velocity
or Hydraulic
Gain resolution
Absolute position range
Rate
Update Period
Position Loop: PID with Velocity Feedforward
Velocity Loop: PI with Accel Feedforwrd (nested);
with Directional Scaling and Friction Compensation
Position Loop: PID with Velocity Feedforward and
Accel Feedforward with Directional Scaling and
Friction Compensation
Velocity Loop: N/A (handled by Drive or Valve).
32- bit floating point
2
32
(4,294,967,296) transducer counts
500Hz, 666.7Hz, 1kHz, 2kHz, 4kHz (Selectable)
250µsec, 500µsec, 1msec, 1.5msec, 2msec
Module location
1756 ControlLogix chassis
Module keying
Electronic
Power dissipation
5.5W maximum
Thermal dissipation
18.77 BTU/hr
Backplane current
5.1V dc @ 700mA and 24V dc @ 2.5mA
SSI input
Type
Resolution
Electrical Interface
Input impedance
Output Load
Transducer
Clock Frequency
Synchronous Serial Interface
8 to 31 Bits
Isolated 5V differential (RS-422 signal)
215 Ohm differential
100 Ohm minimum
Binary or Gray code
205kHz or 625kHz
Spare Allen-Bradley Parts