Test for proper system operation, Troubleshoot possible problems – Rockwell Automation 1746-QV,D17466.18 OPEN-LOOP VELOCITY CONTL User Manual

Page 24

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5–4

Operating the Module

Publication 1746-6.18 April 1998

ATTENTION: Test for proper system operation to verify that
precautions to guard against unexpected motion perform as intended.
(See Power Supply and Design Considerations in chapter 4)

Because of the wide variety of applications for this module, we leave
the procedural details to you.

Look for proper system operation as you test for these conditions:

controlled system startup/shutdown when turning hydraulics on/off

startup/shutdown of ac to power supplies
(

"15V dc, SLC chassis, and 24V dc)

loss of LDT input

effect of the last-state-of-output bit (G-file, word 5, bit 13)
regarding one or more of the above

Using Status Bits for Errors Detected by the Module

The module is designed to detect and indicate status as follows
(in the input image table word I:e.0 or N7:60 in the ladder program):

hardware operational faults

data entry errors when entering setpoints or setting control bits

acknowledgement of stored setpoints

Important: To clear error bits, toggle N7:50 from 0 to 16 to 0.

Bit #:

Description: (for error & fault bits 0-8, status of 0 = OK, status of 1 = fault.)

0

The module sets this LDT error bit when it detects a:
– broken or mis-wired LDT cable
– faulty LDT
– incompatible LDT type (DPM or RPM)
– missing LDT magnet
– loss of

"15V dc PS

1

Module fault, such as EEPROM error. May turn outputs OFF (fault dependent)

2

The module sets this bit when it detects any of the following invalid command bits
or bit combinations in output image table word 0 (O:e.0):
– one or more of the reserved bits 9-15 were set
– bit 5 or 7 (position) was set concurrently with bit 6 or 8 (voltage)
– output enable bit 0 (extend) or 1 (retract) was set before loading valid profiles
– both output enable bits 0 (extend) and 1 (retract) were set concurrently
– started to run a profile after the module had flagged an LDT error (I:e.0/0)

3

You set one or more of the reserved bits 0-13 in G-file word 5 (Ge:5).

4

You entered an invalid length (word 3) or count (word 4) in the G file.

5

You entered an invalid LDT calibration (words 1 and/or 2) in the G file.

6

You entered position setpoint outside the range –32,768 to +32,767 in O:e.1-O:e.7.

7

You entered a voltage value outside the range of

"10,000mV in O:e.1-O:e.7.

8

Loss of sensor. The module detected position data (in I:e.1) greater than the LDT
length plus the preset reference. Clear this bit by running a profile.

9-11

Reserved. Do NOT use.

Test for
Proper System Operation

Troubleshoot
Possible Problems

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