adccommunitymod (AutomationDirect) asked a question.
EZT "Protocol Error"
Created Date: April 11,2005
Created By: Tom Schmidt
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I have two systems (different applications) using a DO-06DD1 PLC coupled to a EZ-S6C-K EZT panel. Both systems work fine except one has "Protocol Error " pop up every 30 seconds or so and this re-activates the screen from screen-saver time-out mode. Could this error be caused by a firm-ware version issue?
Created Date: April 11,2005
Created by: Tom Schmidt
I have two systems (different applications) using a DO-06DD1 PLC coupled to a EZ-S6C-K EZT panel. Both systems work fine except one has "Protocol Error " pop up every 30 seconds or so and this re-activates the screen from screen-saver time-out mode. Could this error be caused by a firm-ware version issue?
Created Date: April 12,2005
Created by: Tech Guy
It could be, but a more likely explanation is noise or possibly not having a large enough power supply (1.2 amps minimum with nothing else using it).
If it is noise, it could be getting induced on the communications cable or power supply. Common causes are unsuppressed solemoids, welders, VFDs, or other high frequency or high current devices.
Created Date: April 12,2005
Created by: Tom Schmidt
Thanks Tech Guy,
I am using the recommended PS24-050D supply to power the EZT only, and have MOV's on the solenoids in this system.
Created Date: April 13,2005
Created by: Tech Guy
Make sure that your communications cable and power supply wiring are not ran parallel to any high amperage or high frequency devices as well.
Created Date: April 13,2005
Created by: GKiser
Doesn't the "0x0008 Protocol error " most of the time mean:
- The PLC is in RUN mode (instead of TERM)?
- The PLC has a password?
I may be way off here, but just thinking out loud.
Greg Kiser
Host Engineering, Inc.
Created Date: April 14,2005
Created by: Tech Guy
Gkiser,
It could be that as well, but since this user says that it is only "occasionally " happens it most likely will be one of the two items that I mentioned previously.
If it was constantly on the screen, then yes, you are correct.
Created Date: April 14,2005
Created by: marksji
Actually I 've found that systems with a password or switch in RUN don't consistently show protocol error. I 've actually had a few systems run entire seasons in RUN with a password and not have a problem, but even then it does eventually show up.
Created Date: April 22,2005
Created by: C R Williams
Seen this several times, in the s/w lab too, which does not have any opower switching devices. Followed all the recommended and customary power supply, shielding, and grounding recommendations. I'm wondering if there's an synchronicity (?) condition between the relatively slow serial interface and the main plc program loop, as I have noticed that this error is frequent (say 2 - 3 times an hour) with some programs and infrequent with others (everything else being more or less the same).