Manual

Troubleshooting
Chapter 10
103
The 1771-ES expander module has six indicators (Figure 10.2):
Module active - This green indicator is on when the 1771-ES expander
is operating normally.
Marker - This green indicator is on when the 1771-ES expander
detects the encoder marker signal. Note that this indicator turns on
only if the signal from encoder channels A and B are true when the
marker signal is true unless you set the marker-logic jumper for
ungated.
Home - This green indicator is on when the axis is at the home
position.
Tachometer calibrate (TACH CAL) - This green indicator is used in
setting up the loss-of-feedback detection feature (see section titled
“Tachometer Calibration,” chapter 9).
Hardware stop (HDW STOP) - This red indicator goes on when the
hardware stop input is on. It stays on until the 1771-ES expander is
reset.
Diagnostic (DIAG) - This red indicator goes on when the 1771-ES
expander detects a module fault.
At power up, the module active, marker, home, hardware stop, and
diagnostic indicators all flash on then off. They stay off while the module
performs power-up diagnostics. If diagnostics detect no problem, the
active indicator turns on.
Figure 10.2
1771ES
Expander Indicators
SERVO
EXPANDER
(ENCODER)
SERVO
EXPANDER
(ENCODER)
Module Active (Green)
Marker (Green)
Home (Green)
Tach Calibration (Green)
Hardware Stop (Red)
Diagnostic (Red)
Monitoring 1771ES Expander
Indicators