Rockwell Automation T6200 Compressor Anti-Surge and Capacity Controller - Manual (Page 21)

Input/Output Circuit Description
2-9
Discrete Outputs with External Power
In reference to Figure 2-8, the discrete transistor output with an external power source can sink up to 0.25
amperes continuously and one ampere momentarily. The maximum voltage that can be applied
continuously is 38 volts DC. The return (-) of the external power source must be connected to the “-”
input or “-” power terminal of the T6200 Controller.
1A
1A
Latch
1A
100V
Primary Control Board
1A
100V
Termination
Panel
Backup Control Board
Output from
Microprocessor
RS
Active from Figure 2-9
Inhibit from Figure 2-9
<0.25A
Load
Latch
Output from
Microprocessor
RS
Active from Figure 2-9
Inhibit from Figure 2-9
Active/Standby Logic
The active/standby logic determines which control board (primary or backup) is active and if the outputs
are active. Only one control board can assume the active role at any given time. Refer to Figure 2-9.
The inhibit signal is true when the control board is not active and the system fail signal is true. The inhibit
signal when true will reset the analog outputs to zero and reset the discrete output latches causing the
output transistors to open.
The only time the inhibit signal can be true, in a primary control board that does not have a good control
board in its backup position, is the first 0.2 second after power is first applied. This will allow the outputs
to reset on power up and to freeze the outputs if the system fail signal should become true when the
control board is active and must remain active.
Discrete Output
with External
Power
FIGURE 2-8.