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Author Topic: BX-DMIO Error Slot 255  (Read 16403 times)

JeffS

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BX-DMIO Error Slot 255
« on: November 06, 2025, 04:38:47 PM »
I have a remote IO module reporting a configuration mismatch on Slot 255.  I tried re-writing booter/firmware, reset defaults, rewrote booter/firmware to the BRX Master with no luck.  I am assuming this remote IO module is dead, but wanted to report the odd message.

JeffS

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Re: BX-DMIO Error Slot 255
« Reply #1 on: November 07, 2025, 12:43:51 PM »
So the customer replaced the BX-DMIO and it is still showing an error light on the DMIO and when I log into the BRX PLC I see the same Slot 255 error. 

So at this point I guess the BRX Master is the bad component here, just very misleading as the error points toward the DMIO device?

BobO

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Re: BX-DMIO Error Slot 255
« Reply #2 on: November 08, 2025, 12:51:01 AM »
So the customer replaced the BX-DMIO and it is still showing an error light on the DMIO and when I log into the BRX PLC I see the same Slot 255 error. 

So at this point I guess the BRX Master is the bad component here, just very misleading as the error points toward the DMIO device?

Slot 255 actually points to the onboard I/O, which there isn't any. It isn't a hardware problem, it's probably garbage in the config. I've been out on vacation, but I'll look into it when I'm back in the office.
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JeffS

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Re: BX-DMIO Error Slot 255
« Reply #3 on: November 10, 2025, 06:29:32 PM »
So I sent them a new PLC and they got the same error.  I had them factory reset the PLC (Dips and RUN/TERM/STOP dance) and I remotely reloaded the program and got the same error.   I am only getting this error at this one site luckily, but so far not able to rectify it.  This setup ran fine last year and nothing has changed on the system (no changed code/sensors/wiring).  They were running 2.9.6 firmware so I did update to 2.10.3 but the error persists.

So at this point we replaced the BX-DMIO and the BX-DM1E-M-D, initially restored the new PLC from a backup of the old PLC, then since the problem persisted, factory reset that PLC using run/stop dance, reloaded from a clean copy, and the problem persists.

Any thoughts on what to check next?

BobO

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Re: BX-DMIO Error Slot 255
« Reply #4 on: November 12, 2025, 03:32:56 PM »
I've been communicating with JeffS off the forum, but to complete the public record, we found a bug in the Ethernet Master where in certain conditions (rare, I think), the master sent a malformed request that resulted in this symptom. The fix will be in the next OS to be released shortly.
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

Kristjan

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Re: BX-DMIO Error Slot 255
« Reply #5 on: December 14, 2025, 12:15:37 PM »
Today we got the Slot 255 Error. This is a system that has been running for several months with no glitches. I updated firmware (from 2.9.x to 2.10.2) and gate array but was unable to get it to RUN mode because of the error. After power cycle on the PLC, it came back with no errors and it went right into RUN mode, all looks good.

Is the Ethernet Master bug also present in firmware 2.11?

BobO

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Re: BX-DMIO Error Slot 255
« Reply #6 on: December 14, 2025, 11:48:57 PM »
Today we got the Slot 255 Error. This is a system that has been running for several months with no glitches. I updated firmware (from 2.9.x to 2.10.2) and gate array but was unable to get it to RUN mode because of the error. After power cycle on the PLC, it came back with no errors and it went right into RUN mode, all looks good.

Is the Ethernet Master bug also present in firmware 2.11?

So you got this on 2.10.2? Or 2.9.x?
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

Kristjan

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Re: BX-DMIO Error Slot 255
« Reply #7 on: December 15, 2025, 03:26:33 PM »
The error occurred on 2.9.x.

I upgraded the firmware before power cycling but I don't know if the firmware update was neccessary, maybe a power cycle on 2.9.x would have fixed it.

BobO

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Re: BX-DMIO Error Slot 255
« Reply #8 on: December 17, 2025, 12:34:34 AM »
The error occurred on 2.9.x.

I upgraded the firmware before power cycling but I don't know if the firmware update was neccessary, maybe a power cycle on 2.9.x would have fixed it.

Did you upgrade EBC/DMIO before it happened?
"It has recently come to our attention that users spend 95% of their time using 5% of the available features. That might be relevant." -BobO

Kristjan

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Re: BX-DMIO Error Slot 255
« Reply #9 on: December 18, 2025, 08:20:44 AM »
I only upgraded firmware on the PLC/DM1E. Didn't upgrade the DMIOs (I have two of those). Works like a charm now.

Kristjan

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Re: BX-DMIO Error Slot 255
« Reply #10 on: January 05, 2026, 11:27:07 AM »
Today we had another stop on the PLC that previously gave me the Slot 255 error. Unfortunately, I was unable to remotely connect to the system and thus unable to inspect the error. But I suspect another occurence of the Slot 255 error. The operator power cycled the PLC and the system is now up and running.

Is there any planned release date for the fix?


MikeS

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Re: BX-DMIO Error Slot 255
« Reply #11 on: January 05, 2026, 01:00:16 PM »
v2.11.2 contains the fix we made for that problem. It's available for download through Help -> Check for Updates.
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Kristjan

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Re: BX-DMIO Error Slot 255
« Reply #12 on: January 06, 2026, 04:47:32 AM »
Great, thank you!

This is a fix for the PLC (DM1E), right? Do I need to update the DMIOs too?

MikeS

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Re: BX-DMIO Error Slot 255
« Reply #13 on: January 06, 2026, 08:33:44 AM »
Correct, it is only a fix for the CPU. As a general rule, we recommend keeping the DMIOs up to date on firmware.
Good design costs a lot. Bad design costs even more.