Transmission error bit in PMCR

[lchamarthi 2]

Hi All, I have 13 nodes where I am polling 13 PMCR instructions to read and write data successfully with a counter.I have generated error for nodes in problem/not connected physically/comms break when I use/ selected all 13 nodes. This i have done with keep instruction with the input of transmission error falg (1633.15 as Unit 5) and reset with normal complete flag(1634.11). Node #1 error is getting detected at its PMCR's execution completion and before to next PMCRs start. simple way to tell. when Polling counter is at #2 , then transmission error flag is high, when slave 1 not physically connected or comms problem case. I may not use all 13 nodes sequentially and randam I select what ever i require from HMI, called as required in my program. In this case i am getting problem in generating errors. I will attach code for better reference. Kindly go through and suggest me some ideas. Thanks Untitled.cxp Edited 17 Sep 2009 by lchamarthi

[PMCR 66]

chamarthi I am not on a PC with CX Programmer to look at your code, so I will describe the solution, and draw with MS Paint. Set aside 1 bit per node number to know which node is actively communicating.. Exampel: W0.00 = node 1, W0.01 = node 2 etc. When you trigger a PMCR for a specific node, set the corresponding bit. For completion, use the trailing edge of the port busy bit (1634.15) to know when the PMCR is finished, and 1634.10 (NG) and 1634.11 (OK). Make certain that this code is above (before) the actual PMCRs for proper sequencing. l

[lchamarthi 2]

Hi PMCR, Thanks for your immediate reply. I have tried out but didn't work out, may be something i am missing. Actually what my analysis is if i execute all nodes PMCRs and generate error, then it will fine. But I want skip to excute PMCRs for not required ones and execute only required ones, as i know these slave numbers can selected from HMI and i am bypassing as said in program to increase the speed. But generating errors to only required/selected nodes is becoming problem. I would appreciate if anyone could look into code and give some suggestions. Or in other words, how to generate slave error, when couter value is at respective node considering all the slaves programming done but selection of HMI slaves only shoulld be in active state.This i have done bypassing of counter successfully but generating error is the problem when counter at same slave id. Thanks for the help! Edited 18 Sep 2009 by lchamarthi

[PMCR 66]

In the PMCRs that you are trying to trap for errors, how are you passing the node number? In your original post, which PMCR are you using? The one marked 'Dummy'?

[lchamarthi 2]

Edited 21 Sep 2009 by lchamarthi

[PMCR 66]

2 Things that I see in the ladder code that could be a problem. 1. You are incrementing the PMCR Counter on the rising edge of the port busy bit (1634.15). As soon as the PMCR starts, you move to the next step. I would change the rising edge to a trailing edge of 1624.15, so the step counter stays at the current step until the next PMCR is ready to trigger. 2. In the ladder, you are checking the error bits after incrementing the step counter. Increment Step Counter Check for Errors Trigger PMCR I think that you want to Check for Errors Increment Step Counter Trigger PMCR See the modified code. I moved the incrementing of the step counter to after the error checking. I changed the incrementing of the step counter from rising edge to trailing edge. I chaned the step numbers in the error checking to match the true step numbers. Note: I did not have a chance to test this code. Untitled2.cxp

[lchamarthi 2]

I appreciate your efforts. I have tested this on machine but couldn't help. Also I tried selecting only slave 1 and rest of slaves unselected from HMI i.e, polling counter always 1. In this case I tried disconnecting physical slave hardware from communication, but error was not set in PLC ladder. Even if there is a sequence abort flag setting error, immediately I have seen Normal complete flag resetting it. I am not understanding this scenario that why Normal complete flag becomes high even though Slave physically not presented. Could you please look in to help me. Thanks

[PMCR 66]

lchamarthi Please post or PM me your Protocol Macro. The answer could be in there.

[lchamarthi 2]

PMCR! How to attach a file while sending personal mail? There is a text shows "attachment editor" but no link to attach a file Edited 24 Sep 2009 by lchamarthi

[PMCR 66]

You can add an attachment just like a regular post. Click Browse, select the file, then click Upload The picture below is from a private message dialog box. Edited 24 Sep 2009 by PMCR

[lchamarthi 2]

Hi! I am not seeing any browse link as shown in the picture.Only seeing Attachment editor and Options text and nothing else. Or else please provide me your Id as I will give my mail Id. lakshmi.chamarthi@gmail.com

[smario 0]

do you succed? i have 4 slaves and i also cannot read error bit on PMCR