User`s manual

535 User's Manual Chapter 7 83
Applications
F. STAGED OUTPUTS
With staged outputs, one analog output can vary its signal (e.g., 4-20 mA) over
a portion of the PID output range. The second analog output then varies its signal
over another portion of the PID output range. This is an excellent method to
stage two control valves or two pumps using standard control signal ranges.
Hardware Configuration
• The controller must have analog output modules installed in the first two
output sockets.
Software Configuration
1. Go to the CONFIG. menu.
Set CTRL. TYPE to STAGED.
2. Go to the CONTROL menu.
3. For OUT1 STOP, specify where the first output reaches 100%.
4. For OUT2 START, specify where the second output begins.
G. RETRANSMISSION
The retransmission feature may be used to transmit a milliamp signal
corresponding to the process variable, target setpoint, control output, or actual
setpoint to another device. A common application is to use it to record one of
these variables with a recorder.
Hardware Configuration
• There must be an analog module installed in output socket 2, 3 or 4.
Software Configuration
Up to two outputs can be configured for retransmission. The menu will scroll
through the configuration parameters for specified value “X” (2, 3 or 4).
1. Go to the CONFIG. menu.
2. For OUTPUT:2, OUTPUT:3 and OUTPUT:4 parameters, set one or two of
them to RETRANS.
3. Go to the RETRANS. menu.
4. Set the corresponding parameter, TYPE:X, for the first retransmission out-
put to define what is being transmitted: the process variable, setpoint, ramp-
ing setpoint or output.
PID Outpu
t
4 mA
20 mA
100%50%33%0%
Output 1
Output 2
Figure 7.10
Staged Outputs Example
OUT1 STOP was set to 33% and
OUT2 STRT. was set to 50%.
NOTE: For an analog output module
for retransmission that was not factory-
installed, calibrate the output for
maximum accuracy. Refer to
Appendix 4 for details on calibration.