MODEM COMMUNICATION TO ABB RELAYS
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REMOTE MODEM
The configuration requirements for the remote modem vary slightly from the local modem. The
configured commands in the REMOTE modem are illustrated in Figure 49. The parameters configured in
your remote modem may be accessible using the command AT&I4. It is important to connect the
HYPERTERMINAL program to the modem being configured as REMOTE to accomplish this. It is also
advisable to label the modem as being a REMOTE device for identification purposes only.
The remote modem should have all its handshaking requirements turned off. Additionally, the
COMMAND MODE ECHO and the ONLINE MODE ECHO must be disabled. Failure to disable these
parameters will lockup the buffer of the modem and the REL512 since the connect strings, REL512 time
ASCII strings (on a 1 minute basis) will be returned to the REL512 for response.
The important command strings to configure are:
•
DISABLE DTR (&D0)
•
USE THE DEFAULT DISABLE OF SOFTWARE FLOW CONTROL (&I0)
•
DSR ALWAYS ON (&S0)
•
ONLINE ECHO OFF (E0)
•
ONLINE LOCAL ECHO OFF (F1)
•
DISABLE CARRIER DETECT (&C0)
•
DISABLE TRANSMIT FLOW CONTROL (&H0)
•
DISABLE RECEIVED DATA RTS CONTROL (&R1)
•
DISABLE RESULTS CODE (&A0)
The AT command set string should look like this:
AT&D0&I0&S0E0F1&C0&H0&R1&A0&W
As with the previous example, the &W writes the command string to NVRAM.
Since this modem is configured for AUTO ANSWER, certain “S” registers should be configured for
optimal performance. In this example, sample “S “ register values are given as an example. The user
should engineer appropriate values for their application:
•
ATS0=3 (3 Rings before Auto Answer)
•
ATS41=10 ( 10 Attempts before disconnect of Auto Answer)
•
ATS19 = 1 (1 Minute Inactivity causes hang up)
The “S” register definitions are particular to this particular brand of modem. Refer to the website or CD
ROM included with the modem to verify correctness. As explained previously, the command AT&W
should be sent to the device to write the parameters into NVRAM.
Summary of Contents for REL 356
Page 23: ...ABB REL 356 Current Differential Protection 1 10 Product Overview and Specifications ...
Page 83: ...ABB REL 356 Current Differential Protection 3 36 Settings and Application ...
Page 127: ...ABB REL 356 Current Differential Protection 5 28 Testing ...
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