Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 7)

Introduction
Chapter 1
1Ć4
manual control station of both loops to manual control. The module’s
analog inputs can be read and outputs can be set by the PC processor.
The PID module can draw its +5V DC operating power from either the
chassis backplane power supply or from a user-supplied +5V DC power
supply through the field wiring arm. The external power supply option
permits a more fault tolerant system by allowing the PID module to be
powered independently. The PID module also requires +15V DC power
for the analog circuitry.
Typical PID hardware and signal paths are shown in Figure 1.2.