Hi all....i m new to edaboard forum...i need help regarding MODBUS RTU master modem...i want to interface DSE5510 or DSE7301 controller with modem; to transmit data over internet.We will use RS485..
Right now we are facing difficulty in finding Master Modbus modem. Any help or supporting material in this regard will be highly appreciated...
Initialize the PC GSM Modem, (depending on your polling philosophy), before start of polling or on Modbus startup, and establish link with downstram modem.
2. Configure the RTU GSM Modem in an auto-answer mode, so that it will answer the call when-ever it comes, and shall transparently transfer the data to the RS-232 port on the RTU
If these two steps are OK modbus should work. Please note that the GSM Modem signal levels and RTU RS-232 Signal levels should match, or else the RTU Serial port will not be able to catch the data (GSM Modems have very low RS-232 Signal O/Ps).
Modbus TCP/IP, would be possible if your RTU supports PPP link, and you are able to establish a PPP connection between the two nodes.
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Moore Industries sells both Modbus TCP and Modbus RTU RTUs as well as radio modems. Everything works great with Wonderware too. Plug and play, easy to use. You may want to see what they have available. 818-894-7111. Fieldbus | Signal Conditioners | Temperature Sensors
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