Rockwell Automation 1746-QS,D17466.19 SYNCHRONIZED AXES MODULE - Manual (Page 13)

2–5
Publication 1746-6.19 March 1998
Repeat this procedure to check out each of the four axis loops
connected to the IFM terminal block.
ATTENTION: Be sure to remove all power to the SLC processor,
LDT, valve and pump beforehand.
1. Disconnect the LDT connector at the head end.
2. Disconnect the connector to the IFM terminal block.
3. Turn ON the power supplies for the LDT and SLC processor, and
check the LDT connector and IFM terminal block for:
•
+15V dc
•
PS common
•
–15V dc
4. Observe that the module’s fault LED indicates Green.
5. Verify continuity between IFM COM terminal (50) and each of:
•
shield of the amplifier output cable to the valve
•
output common on
"15V dc PS that powers the LDT
•
(–) terminal on +24V dc PS that powers the proportional amplifier
6. Verify NO continuity between drive output commons connected to
IFM terminals 3, 7, 11, 15 and earth ground.
7. To minimize ground loops, verify that all cable shields are grounded
(at one end, only) to SH terminals of the IFM terminal block, and
that GND terminal (51) of the IFM is connected to earth ground.
1. Design for adequate pressure and volume. Hydraulic systems
must have enough pressure and fluid volume (accumulator) to move the
desired load the commanded distance and speed. Inadequate pressure
or volume will cause the axis to lag the target position as the controller
attempts to move the axis faster than the system can move. Consider
monitoring system pressure or providing a low-limit (approx. 80%)
pressure switch.
2. Avoid flexible hose. Use no flexible hose between the valve and
the cylinder being controlled. Flexible hose will swell and contract
as the valve opens and closes, causing oscillation and loss of control.
3. Mount valve and cylinder in correct orientation. To avoid
problems from entrapped air, mount the valve directly to the cylinder
and positioned above it. Mount pressure sensors beneath the cylinder.
4. Use linear valves with minimal overlap. If using proportional
valves, they should have less than 3% overlap and a linear (not
curvilinear) response. Nonlinear valves or valves with excessive
(20%) overlap may cause oscillation or hunting. We recommend
using servo valves or servo-quality proportional valves.
Checking Out the
Wiring and Grounding
Setting Up the Hydraulics