Mitsubishi PLC Replacement

[mbarrett87]

Hi all, This is my first time using anything to do with mitsubishi and i'm honestly stumped! Our client's current system runs off of a FX2N CPU and a local SCADA screen, My project is to replace the PLC with a FX3U model (this is to add Ethernet capability through the FX3U-ENET) and bring the SCADA onto an archestra system... My main problem is that the code i was supplied from site came with no comments, tags or descriptions, seeing as i'm replacing the CPU this shouldn't be too bad but for the archestra i need to know what the tags are, i've bee able to identify the digital signals from the electrical drawings but i cannot find ANY of the analogue inputs, currently there should be 16 AI signals on the PLC. can anyone point me as to what to look for? i've seen that FROM instructions are used to read these in but i can only find three of these instructions in the code? Thanks

[Gambit]

First you will have to look for the from instruction used in your program ------------------------------------------[From A B C D] Where A is the special module behind de FX CPU. For instance if your PLC configuration is as follows FX2NCPU FX2N- 4AD information from this module the instruction will start with [From K0 .... FX2N--4AD information from this module the instruction will start with [From K1 .... B is the BFM address. You will have to look in the specific analog modules manual to see on which BFM address the analog signal value is located. C will be the Device to which the analog signal is copied D is a batch of the instruction. For instance: -------------[FROM K0 K1 D0 K1] This will get BFM1 from the first special module and copy that to Device D0 -------------[FROM K0 K1 D0 K4] This instruction will do the same but also copy BFM 2,3 and for and copy those values to D1,D2 and D3 Hope this clears it up a bit for you. Edited June 25, 2013 by Gambit

[mbarrett87]

Hi and Thanks for the reply, the FROM command is only used twice in my entire program T100 ------ [FROM K0 K10 D1000 K8] ¦ [FROM K1 K10 D1010 K8] Is this perhaps reading all of the channels in at once? Edited June 25, 2013 by mbarrett87

[Veganic]

Yes. The first instruction is reading in 8 analogue values from an extension unit in "slot 1" Value 1 -> D1000 Value 8 -> D1007 The second instruction is reading 8 analogue values from an extension unit is "slot 2" Value 1(9) -> D1010 Value 8(16) ->D1017

[Gambit]

You are probably using an 8 channel moduleso Chl1 - D1010 Ch2 - D1011 Ch3 - D1012 Which module are you using then I can check?

[mbarrett87]

Thanks chaps, I belive this is making more sense now

[JRoss]

Also do a search for the TO command which writes to the special function module. This is sometimes used even on some analog input modules for configuration. Also look for the 32-bit versions of both instructions (DFRO and DTO), as they won't turn up in a search for the 16-bit version.