Hello,

I am using this modem with modbus communication. I used SIEMENS library but how can i access to signal strength of MD720-3 ?? I want show it in wincc !

sorry for my terrible English.

Tanks.

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Split from Md720-3 gsm module .

Hello Sepehr,

sry but what HW PLC you're using, via which interface you wnat establish communication, what SW for programming, what type of Modbus? How can we help you if you don't post basic informations? Are you sure that Modbus is available for connection and if yes what register show your needed data? Look for first to documentation to Modem.

Hello Duris,

I used CP341 and SMS_SR_Library. In this library FB18 "SMS_sr_CP_341" is used. every things i need is foreseen in this library but i am looking for "signal strength" status of modem that is not in it. for your question about what type of Modbus, i installed Modbus master and PtP_V5 and in HW i chose ASCII Protocol. i read PDFs about this and i just find AT command for Singnal Strength.

if you have experience in this case i appreciate about that.

Tanks.

Sepehr H

Hello,

I don't have experience, but in this case probably it has nothing to Modbus, you can simply use AT command via user serial communication (FB2,FB3) with ASCII protocol, no Modbus. Look to that documentation how that AT command must look and build frame on array of chars/bytes. Via FB3 you can send that AT command to Modem via serial line and with FB2 you'll receive some frame, where you'll have your data - signal. Look to PtP library where you can find needed blocks for user serial communication - FB3 (Send) and FB2 (Recv). Create DB block where you define Array for Send and Array for receive. Sry for that explanation, look if you can use your instructions (SMS library) to make that AT command and send/receive data to/from modem, maybe that PtP blocks FB2,FB3 you don't need to use

Update: but pls using TIA or Step7 v5.x?

Dear Duris,

Tank you for your useful information.

regards,

Sepehr H