Rockwell Automation 1771-PM , D17716.5.18 U MNL 1771-PM CLUTCH/BRAKE MOD - Manual (Page 62)

Field Wiring Arm Connections
Chapter 6
6Ć10
Each dump valve solenoid should draw at least 60mA. If not, connect an
appropriate load resistor in parallel with it. For neatness and safety, we
recommend that you connect the load resistor only at convenient terminal
strips, not at the field wiring arms.
If you use dump valves with internal fault detection (no valve stem
switches) but you have configured for external fault detection, simulate
the inputs of the dump valve stem switches. Do this by jumpering the
input terminals of field wiring arms for dump valve stem switches to the
input terminals for the main valve stem switches. Jumper terminal 4,
module group 4, slot 1 (Figure 6.4 or Figure 6.8) to terminal 0, module
Group 2, slot 0 (Figure 6.2 or Figure 6.6) for chassis A and B.
Micro-inch mode lets you run your press at low speed (1 to 5 strokes per
minute) for setting up dies and making trial runs. Micro-inch mode
requires that you provide a separate drive and clutch/brake assembly to
drive the shaft with the flywheel bypassed. Micro-inch mode functions
only when the main clutch/brake assembly is inoperative, and vice versa.
The advantage of the micro-inch mode operation is full press tonnage
capacity at low press speeds. Other characteristics include:
Micro-inch motion is initiated using INCH buttons.
Micro-inch solenoid valves function only when the mode select switch
is in the MICRO-INCH position.
Diagnostic codes for micro-inch mode are listed in the look-up table.
They are 9-bit binary (3-digit hex) as compared with 8-bit binary
(2-digit hex) for all other diagnostic codes.
Voting processors inhibit main valve, auxiliary valve, and dump valve
solenoids whenever you use micro-inch. Voting processors monitor
these outputs in micro-inch mode to verify they are not on or shorted.
Connect valve solenoids A and B for micro-inch mode as shown in
Figure 6.4 for ungrounded solenoids and Figure 6.8 for grounded
solenoids. If you do not use micro-inch, no connections are needed.
Figure 6.4 and Figure 6.8 also show connections for:
feedback from micro-inch valve solenoid triacs that allows both voting
processors to monitor the on or off state for each triac, check for
shorted or open triacs, and shorted or open solenoids of the micro-inch
valves.
load resistors, LRA and LRB, for triac feedback from micro-inch valve
solenoids.
switch inputs for the mode select switch, valve stem switches, and
pressure switch for micro-inch circuits.
Optional MicroĆinch Valve
Solenoids