YSI IQ SensorNet MIQ/A-MOD Module - Manual (Page 18)

Interface for the Modbus RTU MIQ/(A-)MOD
18 ba76021e01 01/2012
3.2.4 Bus and module monitoring
The Modbus module has 4 LEDs for monitoring the bus and one LED
for monitoring the Modbus module. These 5 LEDs are important aids
for the monitoring and diagnosis of faults.
Bus monitoring The LEDs have the following meaning:
Fig. 3-11 LEDs for bus monitoring
LED Color Meaning
1 Flashes
green Data exchange
(the module receives or transmits data.)
Off No data exchange
2 Red Bus error
(more than 10% of the received telegrams have
wrong CRC values.)
Off The module is operating or not initialized
3 Green Modbus is ready for operation
Off The module is not correctly initialized
4 Red The dip switches are set to invalid values
(all dip switches are set to Off or
to invalid values.)
Off The dip switches are set to valid values
4
1
2
3