Rockwell Automation 1746-BTM Barrel Temperature Control Module User Manual - Manual (Page 14)

Publication 1746-UM010B-EN-P - April 2001
1-2 Getting Started
Features of the Temperature
Control Module The 1746–BTM module provides:
•
4 independent temperature control loops
•
autotune PID loops (one loop or any combination of loops can
be autotuned while other loops are running)
•
a unique start–up algorithm to minimize overshoot
•
an isolated thermocouple (J and K) input for each PID loop
•
16–bit analog–to–digital converter resolution (0.1° resolution)
•
a heat CV signal (for each PID loop) as a numeric % value
•
a cool CV signal (for each PID loop) as a numeric % value
•
a heat CV signal (for each PID loop) as a TPO bit
•
a cool CV signal (for each PID loop) as a TPO bit
•
temperature values in C ° or F °
•
self–calibration (external reference required)
•
user–selectable high and low alarms with dead band for
hysteresis
•
input open–circuit detection
Module Outputs The BTM module sends the control variable (CV) for heating and/or
cooling each loop to the SLC processor’s input image table as both of:
•
numeric value (current CV)
•
time–proportioned output (TPO)
Current CV
Your ladder logic should read the numeric value (current CV), scale it,
and send it to an analog output module to generate the control signal
to an analog temperature control actuator. If using the sample
program look for current CVs in N10:208–211 for loops 1–4. Refer
to Sample Program on page 9-1.
TPO
The module returns the heat TPO (bit 6) and cool TPO (bit 7) in input
image table words 8–11 for loops 1–4. The sample program sends
TPO signals to a digital output module to generate the control signal
to a digital temperature control actuator. Refer to Sample Program on
page 9-1.