Dear Forum,

I am setting up a (sinlge) logo (at the moment) for a startert. The object is to control the logo from a SCADA (Not Siemens). The intention, later, is to make a comple switchboard with multiple LOGO's in eacht starter. For now I have the comple LOGO working. Now comes the difficult part.

I have connected the LOGO to a switch into a small network with my laptop. I have established communication between laptop and LOGO with qMODMaster and can read discrete inputes, coils and holding register. I have succesfully put a analog value on a flag using VM and was able to read the vaule.

Modbus setting was port 510 (not 502) as already mentioned here in the forum. Slave adress does not seem to matter. I can change at random, read is still present. I found the LOGO modbus mapping not quite correct. Output coils start at 8190 for correct mapping. Also the holding register seems to be off.

Now my question: Reading work, but now I want to write to the logo and use this in the program:

1) I have used a network iinput. Wat setting must I enter to get the logo to accept my input?

2) does the value needs to be rewritten or once to be accepted.

Many thanks for the replies in advance.

I have added screenshots and the sample program.

I am using LOGO BA8-FS4 and LOGO soft Comfort V8.2

QModMaster is a client and communicates with slaves, but the Logo network connection also is a client, this will not work. Also don't use any NI's, NAI's, NQ's or NAQ's mapped to the Modbus, the mapping is done only with local Vx.y or VWx. You can access all VM addresses directly with the QModMaster, after you setup a Logo network connection as Modbus server. Maybe i can send you an example later. Look to the attachment for a Modbus implemenation table as Excel file. You can select the registers with offset 0 or 1 depend on needs.

If you want to set an output Q1 directly, than don't connect the input of Q1 and use the right mapping number of the excel file. By the way the Modbus port normally is 502 and works fine, if the connections are made in the right way.

Regards, Scorp

See attachment for a selfmade client on Windows PC and a little servr example for a Logo. Unpack the zip anywhere in a directory, inside you will find micro client.exe with additional files, that is a little client made with Profilab Expert. Micro Server.lsc is a little example for the Logo and Setup example.jpg shows how to change settings in the Profilab program.

If the program seems to hang after first start, then wait several seconds, it is okay. Then change ip-address settings to your Logo and start address to 8193 for Q1 or 8257 for M1. With the switch you select low or high signal, with the button you send the settings. Q1 or M1 will remain in the last state, until you send an other signal or after shutdown of the Logo.

This also is possible with your client/master, but it is possible, that your client needs the addresses beginning with 0 (in the example 8192 or 8256)

Good luck, Scorp