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A customer asked for the creation of a management software that among other functions also provides for the reading of production data from an iskra mt831 counter. The solution I had in mind provides a desktop software that, at intervals of time, use the telit modem through the COM1 serial and AT commands, being able to read the contents of some remote counter registers.
I first tried using hyperterminal (connecting to com1 with the following data: 9600 8N1) and after sending the ATD command number_count the message CONNECT 9600 appears. The system in this state does not seem to respond to any command except the classic +++ for return to program mode.
In data mode I also tried to follow the rules of the IEC 62056 standard by sending the command /? Serial number! but without any answer. Could it be that hyperterminal doesn't show me any responses from the modem or maybe it's some setting I need to set?
Question: are you using the GT863-PY modem connected to the PC and the modem inside the iskra mt831?
We need to know how the commands to be sent are made up. For example, if you need to initialize the communication or if you need CR or LF or CR + LF at the end of the command.
Yes, actually what I try to achieve is a remote reading of some registers of the meter mentioned using a gsm connection made between the telit gt863-py modem connected to the COM1 of my development station and the gsm modem of the meter.
As I said with both hyperterminal and other software of the same type I can overcome the data call with ATDTxxxxxxxx but any attempt to send commands in 62056 standard to the counter does not produce any kind of response from the same.
I tried with an initialization string consisting of 8 NUL characters.
I tried without the aforementioned string but directly with the sequence of characters /? Matriculation! or with the sequence /?!Has anyone ever made this kind of solution?
For our product range SlimLine we have created a special function block that manages the reading of data from Iskra counters using the IEC 62056-21 standard (See postThe IEC 62056-21 protocol specifications are not free, they must be purchased from International Electrotechnical Commission. On the Internet you can find some information about it, and possibly you can contact the supplier of the meter if they can provide an excerpt of the commands. What you have done seems correct to me, the connection is established and to start communication with a meter the sequence is the that you did, but pay attention to the serial mode the standard is 9600, e, 7, 1The connection with the counter starts by sending 8 . A pause of 500 mS is expected. A message is sent with “/? Serial number! ". You receive message" / Manufacturer code and meter type ”. Then we continue with the register reading commands based on the OBIS codes. If the meter also has the RS485 serial port, I recommend testing the communication protocol directly from the serial port before interposing the modem.
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