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suke

Using encoders

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Hello guys Need some help please with interrupt functions. A machine we have is using an encoder connected to inputs 000.00 and 000.01 of a CQM. They are using this encoder to operate an output which in turn is used to make an inverter go to slow speed. How do i find where the settings are to adjust at what point this output is switched on and off. I know if you search for input 000.00 using syswin it does not find it. From my little knowledge do you have to use PRV or CTBL to make the operation work. There are also encoders connected to inputs 000.02 and 000.03 and 000.04 and 000.05. I would have thought that you would have seperate PRV's and CTBL's for each encoder, but searching through the programme of the m/c only reveals one PRV and one CTBL. Can anyone point me in the right direction please Keith

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suke, Welcome to the forum, below is a link to the manual. CQM1 manual @ MrPLC.com Check the manual on input interrupts - counter mode. The instruction would be (@) INT (89). I have not used this instruction, but based on your description (encoders), it might make sense. Inputs 0.00 - 0.03 can be used as interrupts Inputs 0.04 - 0.06 are used as high speed counter inputs, that would explain the PRV and CTBL instruction. Hope this will help. Edited by gtsuport

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TRy this tutorial by Ed Allen: Micro Interrupts and HSC Examples @ MrPLC.com

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Thanks for your help guys. Studying the tutorial now and trying to get my head round it. The Omron manual is not the easiest thing to read and understand. Keith

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Hello again guys Have read the tutorial but still not sure if this is sinking in! Has anyone tried to get the circuit working on slide 28. I think this has been written for a CPM and not a CQM. Having said that the INT(89) where it says at the side is input 000.03 is actually 000,00 in the cqm. So looking further at the slides, whenever input 000.00 goes high it calls subroutine 000 and dm0000 is incremented by 1. Is this correct and can anybody verify that the circuit in the tutorial is correct for a cqm as it doesn't work for me. PS i have set DM6628 to 1111 and DM 6630 to 0100. This is taken from the CQM book and i assume to be correct. Thanks Keith

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Hi Suke, Here is some information from CQM1H series Operation manual (Cat. No. W363-E1-05) CPU Unit built-in inputs (IR 00000 to IR 00003) can be used as high-speed counters without executing interrupt. PVs are stored in SR 244 to SR 247. High-speed pulse input from CPU Unit built-in inputs (IR 00004 to IR 00006) is counted. PVs are stored in SR 230 and SR 231. I haven't done it but possibly the above SR words are used in CMP instruction in your program to operate the inverter output. It's just an idea- see if you could find them in the program. Also look at the SR memory structure- Appendix C in the programming manual- there are other bits to reset PVs, show overflows etc. Edited by atanas

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Hi Atanas It looks as if you are correct. SR230 is indeed in the programme and is compared with a DM area, Still very complicated as the inverter drives the motor at three different speeds and also forward and reverse. I am sure if i stick at it i will now find which settings to change and in which DM area. Thanks for your help. Suke Edited by suke

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