Nortec LINKS 2 GSTC - Manual (Page 32)

28 | Troubleshooting
Troubleshooting
When troubleshooting the communication process for OnLine and/or Links2 modules should be
kept in mind. Humidifier data is first received by the Nortec OnLine module using the modbus
protocol over the serial port connection. It then forwards this data, via modbus/TCP, to the Links2
module over an ethernet link. A router (switch for BACnet/IP applications) Links the two devices
together through their ethernet ports and allows a user to access both devices using only 1
customer installed connection.
Indicator Lights
There is a variety of status LEDs on both the OnLine module and the Links2 module to aid in the
diagnosis of communication problems. Note that communication first occurs between the OnLine
module and the humidifier logic board. The OnLine module then passes information to the Links2
module. If practical, it may be useful to establish a connection with the Nortec OnLine server first
and then establish communication with the Links2 module.