Master-Slave-Arrangement¶
Configuring the Master
To configure the CM574-RCOM as a master device the parameter “Operation mode” must be set to “RCOM Master”. The address or node number must be set to 0 while “Parity” should be “None”. Ensure that “Hayes compatible dial modem” is selected as “Type of modem”. The “Character timeout” should be set to 50 msecs. The value for the “Turnaround time” should be increased to 6000 msecs.
If the CONSOLE port is used (recommended) the parameter “Debug level” of module “CONSOLE” should be set to “Level 2” to obtain detailed information and error messages of the protocol.
Configuring the Slave
To configure the CM574-RCOM as a slave device the parameter “Operation mode” must be set to “RCOM Slave”. The parameter address must be set to a value greater than 0. In this example select 1 for the slave. “Parity” should be “None”. Ensure that “Hayes compatible dial modem” is selected as “Type of modem”. The “Character timeout” should be set to 50 msecs. The value for the “Turnaround time” should be increased to 6000 msecs.
If the CONSOLE port is used (recommended) the parameter “Debug level” of module “CONSOLE” should be set to “Level 2” to obtain detailed information and error messages of the protocol.
Configuring the Modem
The example uses ABB H&IT HSM-ECO remote modems that provide the ability to use both operation modes, RCOM and RCOM+.
Setting up the Phone Book
For both projects the telephone numbers of the RCOM devices must be configured. To use a dial-up modem, a corresponding module has to be appended to the RCOM/RCOM+ module in the PLC configuration as described in the PLC configuration steps of the CM574-RCOM.
Note
For consistency reasons, the phone book of the master as well as the phone book of the slave(s) must be equal.
To add a new entry to the phone book, append a telephone number to the modem. The tab “Module parameters” provides the possibility to set up the corresponding dial prefix identifier and the corresponding telephone number of the node that should be configured.