Rockwell Automation 61C615 RTD Termination Panel - Manual (Page 10)

2Ć2
4
3
2
1
LINEARITY
10V
REF RANGE
SHIELD
SHIELD
OUT A
OUT B
PART OF
INTERFACE
SENSE (LOW)
LOW R
HIGH R (GND)
SHIELD
CABLE
Figure 2.2Ć Typical Input Circuit
A threeĆwire connection to each RTD allows the effects of lead
resistance (up to 5 ohms per lead) to be compensated out. A
separate shield connection is also provided. The shield is grounded
at the termination panel.
The supply for each bridge is modified by the output of a linearizing
amplifier to compensate for both bridge and RTD nonlinearities.
Three potentiometers are included for each channel to adjust offset,
range, and linearity. Nominal full scale is 200 mVolts for a 200 deg. C
span, or 100mVolts, depending upon how the panel is calibrated.