Chapter 7 Using The Rs-485 Port; The Rs-485 Control Commands; The Command Mode - Advantech AMT-73 Installation And Operation Manual

CHAPTER 7
It is recommended that Chapter 3 and Chapter 5 be reviewed to understand the operational features of
this modem prior to setting up the modem.
7.1

The RS-485 Control Commands

The mccontrol command defines which network management application controls the port. The format of
the command MCCONTROL is as follows;
MCCONTROL [ COMMAND | PACKET | NONE ]
The MCCONTROL command parameters are as follows;
COMMAND: In this mode the modem "command" task controls the port. This ASCII protocol is
typically used by a PC to control multiple modems (up to 16) using an RS-485 bus cabling. This
legacy protocol used by the SL-2048™ product is still supported for upward compatibility. The
command mode is supported by all modem types. This protocol is described in Paragraph 7.2 .
PACKET: The packet protocol application controls the RS-485 port. This application is
described in Paragraph 7.3.
NONE: In this mode the RS-485 is unassigned to any control applications.
This is the default manufacturing mode.
The RS-485 port can be set up using either the active front panel (Chapter 4) or from the RS-232
interface (Chapter 5).

7.2 The Command Mode

The AMT-70 modem is upward compatible and still supports the "Addressing Mode" protocol that was
used by the SL-2048™ legacy modems.
With this protocol a client PC can send ASCII requests to one or more modems on an RS-485 bus
using character command mode.
To command a modem on the RS-485 bus, the command must be prefaced with the address 1-255,
then a SPACE. Leading zeros for the address are not required. For the request the address and
command is not be echoed back to the user. The return prompt after the message is received
indicates which modem replied.
EXAMPLE:
<address> <command>
Ex: 023 TBPSK ON
Returns:
AMT-70 023 ON
AMT-70/AMT-73/AMT-75 Installation and Operation
USING THE RS-485 PORT
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