MTS FlexTest Models 200 - Manual (Page 272)

MTS FlexTest® Models 40/60/100/200 Controller Hardware
Model 494.79 8-Channel Valve Driver Board
Digital I/O and Transition Boards 272
Specifications–Model 494.79 8-Channel Valve Driver Board
The Model 494.79 8-Channel Valve Drive board only supports two-stage
valves.
P ARAMETER S PECIFICATION
Output Current Software-configurable output current settings: 25 mA, 50 mA, or 75 mA.
Note If other output currents are required, call MTS about board
modifications.
Valve Outputs per Channel 1
Dither
Frequency
Amplitude
1–4915.2 Hz (software adjustable)
0–5 V DC (software adjustable)
Valve Clamping A software-configurable valve clamping circuit performs the following
actions when an interlock or E-Stop occurs:
Disabled—Valve does not clamp. This is the default action if the clamp
entry is omitted.
Zero—Clamps the servovalve to zero—if valve balance is used, it will
clamp to this value.
Positive—Clamps the servovalve to positive 50% spool opening on a 2-
stage valve driver.
Negative—Clamps the servovalve to negative 50% spool opening on a 2-
stage valve driver.
Cable Loss Detection
Circuits An interlock occurs when a cable loss is detected.
Valve Driver Cable–Each valve driver has a cable-loss detection circuit
that consists of an extra wire that loops out to the valve and back to the
Model 494.79 Valve Driver. This circuit detects if the valve cable is
unplugged from the controller or if the cable has been cut. This circuit will
not detect when the cable is unplugged at the valve.
Transition Cable–The Model 494.79 board also has a cable-loss detection
circuit that senses a disconnect or break in the cable that runs from the
Model 494.46 D/A Converter to the Model 494.79 transition board.
Valve Balance Offset +/- 10 V DC (software adjustable)