The terminal port on Premium PLCs is compatible with a modem connection in all protocols: Master Uni-Telway, Slave Uni-Telway, and Character string.
The modem to be connected must have the following characteristics:
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Support 10 or 11 bits per character if the terminal port is used in Uni-Telway mode:
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Operate without any data compression if the terminal port is used in Uni-Telway.
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Be able to be "forced DTR signal" configured for its RS 232 serial port (if the modem is used in response mode), as this signal is not connected by the cable.
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Operate without flow control (neither hardware: RTS/CTS, or software: XON/XOFF) for its RS 232 serial port, as the cable to be used for the terminal port can only carry TX, RX and GND signals.
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Operate without data carrier check.
NOTE: This operating mode also uses RTS and CTS control signals.
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Accept an incoming telephone call while characters arrive at its RS 232 serial port (if a modem/telephone network is used in response mode on a terminal port configured in master Uni-Telway).
NOTE: We strongly recommended that you check with your dealer that the above-mentioned characteristics are offered by the intended modem.
Connecting to a Premium PLC:
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In Master Uni-Telway mode with the terminal port connected to a modem/telephone network in response mode, this modem must have all the above characteristics (1 to 6).
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In character string mode with the terminal port connected to a modem via a specialized line, this modem must have the characteristics of 3 to 5 above.
Configuring the Terminal Port
In Uni-Telway mode, the following parameters must be observed and set in the configuration in Control Expert software:
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The wait timeout must be between 100 and 250 ms
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In master mode the number of configured slaves must correspond to the actual number of slaves present on the bus.
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In slave mode the number of addresses must correspond to those used.
