Page 317 - Programmable Logic Controllers, Fifth Edition - Mobile version

Output module
Yes
Output Turn OFF Output device Turn ON
0 4 8 12 would not
1 5 9 13
2 6 10 14
3 7 11 15
L1 Output OFF Check I/O ON Output
status device wiring status
VAC indicators indicators
Out 0
Out 1 ON OFF
Out 2 O:2/3
Out 3 R Blown fuse ON Find out why
Out 4 • Repair
Out 5 indicator • Replace
Out 6
Out 7 O:2/8 L2 OFF
Out 8 G
Out 9 Display Display
Out 10
Out 11 rung on rung on
Out 12 screen screen
Out 13
Out 14
Out 15
AC Is output Check I/O Is output
COM No Yes
instruction • Modules instruction
true? • Swing arm true?
• Power
Yes • Rack No

Figure 13-30 Troubleshooting tree for a discrete output module.

If Your Input And Your Input
Circuit LED Is . . . Device Is . . . And Probable Cause

On/Closed/Activated Your input device will not Device is shorted or damaged.
ON turn off.
Your program operates Input circuit wiring or module.
Input
as though it is off. Input is forced off in program.
0 4 8 12
1 5 9 13 Off/Open/Deactivated Your program operates Input device off-state leakage current exceeds
2 6 10 14 as though it is on and/or input circuit specification.
3 7 11 15 the input circuit will not Input device is shorted or damaged.
turn off.
Input circuit wiring or module.
On/Closed/Activated Your program operates Input circuit is incompatible.
OFF as though it is off and/or Low voltage across the input.
the input circuit will not Input circuit wiring or module.
Input turn on.
Input signal turn-on time too fast for input circuit.
0 4 8 12
1 5 9 13 Off/Open/Deactivated Your input device will not
2 6 10 14 turn on. Input device is shorted or damaged.
3 7 11 15 Input is forced on in program.
Your program operates
as though it is on. Input circuit wiring or module.

Figure 13-31 Input troubleshooting guide.

298 Chapter 13 PLC Installation Practices, Editing, and Troubleshooting

pet73842_ch13_281-304.indd 298 03/11/15 7:23 PM