Host Engineering Forum
General Category => Do-more CPUs and Do-more Designer Software => Topic started by: Bolt on October 05, 2023, 05:06:10 PM
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2 weeks ago, a customer called saying a BX-DM1E-18ED23-D (2.9.6) controlled system was acting funny. I logged in, and sure enough, it was, WX0 (configured 4-20mA) was reading 32767 continually. I adjusted a few timer setpoints and they could keep running without it. I visited the site 2 days later, opened the unblown 32mA fuse, put DMM leads in it's place, and found it to be reading correctly, while the BRX kept showing 32767 in WX0, regardless of open circuit or complete 4-20mA loop. Replaced CPU with a spare, everything functioned as intended. (I never did power cycle the machine/PLC, I didn't wan't to shut them down anymore than necessary, but judging by the System Info, the operator restarted it all plenty that morning. Adjacent machine had no power cycles, so it was not likely input power related.
Today, I put the BRX on my test bench, and it will read 6553 at 4mA or open circuit, and 32744 at 19.98mA, so it reads as it should. Any ideas as to what gives? Is this unit perfectly fine or what else can I test?
System Info:S771, Thu Aug 24 04:34:54 2023, System was turned on
S772, Thu Aug 24 04:34:54 2023,
S773, Thu Sep 14 19:19:52 2023, System was turned off
S774, Thu Sep 14 19:19:55 2023, System was turned on
S775, Thu Sep 14 19:19:55 2023,
S776, Thu Sep 14 19:20:00 2023, System was turned off
S777, Thu Sep 14 19:20:13 2023, System was turned on
S778, Thu Sep 14 19:20:13 2023,
S779, Mon Sep 18 05:19:44 2023, System was turned off
S780, Mon Sep 18 05:19:57 2023, System was turned on
S781, Mon Sep 18 05:19:57 2023,
S782, Mon Sep 18 05:28:30 2023, PLC rebooted following hardware watchdog timeout.
S783, Mon Sep 18 05:28:30 2023, System was turned off
S784, Mon Sep 18 05:28:30 2023, System was turned on
S785, Mon Sep 18 05:28:30 2023,
S786, Mon Sep 18 06:09:27 2023, System was turned off
S787, Mon Sep 18 06:10:17 2023, System was turned on
S788, Mon Sep 18 06:10:17 2023,
S789, Mon Sep 18 07:35:50 2023, System was turned off
S790, Mon Sep 18 07:35:54 2023, System was turned on
S791, Mon Sep 18 07:35:54 2023,
S792, Mon Sep 18 13:13:46 2023, System was turned off
S793, Mon Sep 18 13:14:34 2023, System was turned on
S794, Mon Sep 18 13:14:34 2023,
S795, Mon Sep 18 13:20:01 2023, System was turned off
S796, Mon Sep 18 13:20:06 2023, System was turned on
S797, Mon Sep 18 13:20:06 2023,
S798, Mon Sep 18 19:29:24 2023, System was turned off
S799, Mon Sep 18 19:29:38 2023, System was turned on
S800, Mon Sep 18 19:29:38 2023,
S801, Mon Sep 18 19:58:13 2023, System was turned off
S802, Mon Sep 18 19:58:17 2023, System was turned on
S803, Mon Sep 18 19:58:17 2023,
S804, Thu Oct 05 14:28:12 2023, I/O configuration updated
S805, Wed Sep 20 09:24:06 2023, System was turned off
S806, Thu Oct 05 14:28:12 2023, System was turned on
DST400-409:
DST400 1400
DST401 1075183616
DST402 806
DST403 1075183616
DST404 806
DST405 1075183616
DST406 806
DST407 1075183616
DST408 806
DST409 1075183616
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2 weeks ago, a customer called saying a BX-DM1E-18ED23-D (2.9.6) controlled system was acting funny. I logged in, and sure enough, it was, WX0 (configured 4-20mA) was reading 32767 continually. I adjusted a few timer setpoints and they could keep running without it. I visited the site 2 days later, opened the unblown 32mA fuse, put DMM leads in it's place, and found it to be reading correctly, while the BRX kept showing 32767 in WX0, regardless of open circuit or complete 4-20mA loop. Replaced CPU with a spare, everything functioned as intended. (I never did power cycle the machine/PLC, I didn't wan't to shut them down anymore than necessary, but judging by the System Info, the operator restarted it all plenty that morning. Adjacent machine had no power cycles, so it was not likely input power related.
Today, I put the BRX on my test bench, and it will read 6553 at 4mA or open circuit, and 32744 at 19.98mA, so it reads as it should. Any ideas as to what gives? Is this unit perfectly fine or what else can I test?
System Info:S771, Thu Aug 24 04:34:54 2023, System was turned on
S772, Thu Aug 24 04:34:54 2023,
S773, Thu Sep 14 19:19:52 2023, System was turned off
S774, Thu Sep 14 19:19:55 2023, System was turned on
S775, Thu Sep 14 19:19:55 2023,
S776, Thu Sep 14 19:20:00 2023, System was turned off
S777, Thu Sep 14 19:20:13 2023, System was turned on
S778, Thu Sep 14 19:20:13 2023,
S779, Mon Sep 18 05:19:44 2023, System was turned off
S780, Mon Sep 18 05:19:57 2023, System was turned on
S781, Mon Sep 18 05:19:57 2023,
S782, Mon Sep 18 05:28:30 2023, PLC rebooted following hardware watchdog timeout.
S783, Mon Sep 18 05:28:30 2023, System was turned off
S784, Mon Sep 18 05:28:30 2023, System was turned on
S785, Mon Sep 18 05:28:30 2023,
S786, Mon Sep 18 06:09:27 2023, System was turned off
S787, Mon Sep 18 06:10:17 2023, System was turned on
S788, Mon Sep 18 06:10:17 2023,
S789, Mon Sep 18 07:35:50 2023, System was turned off
S790, Mon Sep 18 07:35:54 2023, System was turned on
S791, Mon Sep 18 07:35:54 2023,
S792, Mon Sep 18 13:13:46 2023, System was turned off
S793, Mon Sep 18 13:14:34 2023, System was turned on
S794, Mon Sep 18 13:14:34 2023,
S795, Mon Sep 18 13:20:01 2023, System was turned off
S796, Mon Sep 18 13:20:06 2023, System was turned on
S797, Mon Sep 18 13:20:06 2023,
S798, Mon Sep 18 19:29:24 2023, System was turned off
S799, Mon Sep 18 19:29:38 2023, System was turned on
S800, Mon Sep 18 19:29:38 2023,
S801, Mon Sep 18 19:58:13 2023, System was turned off
S802, Mon Sep 18 19:58:17 2023, System was turned on
S803, Mon Sep 18 19:58:17 2023,
S804, Thu Oct 05 14:28:12 2023, I/O configuration updated
S805, Wed Sep 20 09:24:06 2023, System was turned off
S806, Thu Oct 05 14:28:12 2023, System was turned on
DST400-409:
DST400 1400
DST401 1075183616
DST402 806
DST403 1075183616
DST404 806
DST405 1075183616
DST406 806
DST407 1075183616
DST408 806
DST409 1075183616
The only thing interesting in the log is the watchdog reboot. One thought is that the channel somehow ended up in voltage mode and was reading weird, but I'm grasping. In some early -36 models there was a small susceptibility to that happening, but I don't think it ever happened in either -10 or -18.
If the unit is reading fine in both voltage and current modes, I'd say it's fine. I would definitely check both though.
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If the unit is reading fine in both voltage and current modes, I'd say it's fine. I would definitely check both though.
Bench tested current, switched to voltage, and back to current, and it did just fine.