Schweitzer Engineering Laboratories SEL-701 - Table 10.6 Relay Does Not Respond to Command from Device Connected to Serial Port

Date Code 20010719 701 Motor Protection Relay
Maintenance & Troubleshooting
Troubleshooting Procedure
10.7
Relay Does Not Respond
to Commands From Device Connected to Serial Port
Table 10.6 Re lay D oes Not Res pond to Comm and from Device Connected to Se rial Port
Relay Does Not Respond to Faults
Table 10.7 Re lay D oes Not Res pond to Faults
Table 10.6
Relay Does Not Respond
to Commands From Device Connected to Serial Port
Possible Cause Solution
Communications device not
connected to relay.
Verify cable connections.
Relay or communications device at
incorrect baud rate or other
communication parameter
incompatibility, including cabling
error.
Verify terminal setup and cable pinout.
Relay serial port has received an
XOFF, halting communications.
Type
<CTRL>Q
to send relay on XON and
restart communications.
Rear-panel serial port protocol set
differently than expected.
If you select Modbus
®
protocol, the rear-panel
EIA-232 serial port is disabled. Use the
EIA-485 port to communicate with the relay
using Modbus, or use the front-panel EIA-232
port to communicate with the relay using
ASCII text. See
Section 4: Setting Calculation
for more information on serial port
configuration.
Table 10.7 Relay Does Not Respond to Faults
Possible Cause Solution
Relay improperly set. Verify relay settings.
Improper test source settings. Verify test source settings.
CT or PT input wiring error. Verify input wiring.
Failed relay self-test. Use the front-panel Status of Relay function to view
self-test results.