AIR XD has configurable MODBUS baud rates that can be configured by going to Settings > Communications > RS485/MODBUS > Set Baud Rate
AIR XD instrument baud rate can be selected and assigned from a pre-configured list of options:
The AIR XD instrument address is user selectable and can be configured between 001 and 255.
To see the device address goto Settings > Communications > RS485/MODBUS > Set MODBUS Address as show below:
The AIR XD instrument parity bit can be selected and assigned from a pre-configured list of options.
To set the communications parity, go to Settings > Communications > RS485/MODBUS > Set Parity as show below:
The connection status of the AIR XD can be viewed by pressing ‘Left’ arrow key when on the PM value readings screen. The status screen lists the connection type, connection status and instrument IP address:
By default, the instrument is configured to request an IP address using DHCP. This requires that a DHCP server is also on the network that can assign the IP address. Firewall settings must allow outgoing traffic on selected port numbers.
Note: the MODBUS TCP communicates over ‘Port 502’
By using the dynamic IP assignment option, this prevents the instrument from IP address clashes where it may hold the same IP address as another device. It also allows for minimum configuration of the instrument before install, however the device could be assigned different IP addresses on each power cycle or on address lease timeouts which may prevent the MODBUS TCP client from communicating without further manual changes.
One workaround to prevent a changing IP address is to change router/DHCP server settings to reserve an IP address for the MAC address of the instrument.
Example network setup:
For applications where the AIR XD requires constant access to the MODBUS TCP client server or applications where a DHCP server is not available on the network, the use of a static IP is recommended. To set up the AIR XD to use a static IP, use the following steps:
To check the IP address of the instrument either go to the Network status screen or hold the ‘left’
key while the particulate data is displayed.
Example network setup:
6.1 Check Status
If communication cannot be established with the AIR XD, check the network status screen for information on the unit’s connection status:
If the unit is in the ready or connected state, the instrument is ok and can communicate on the network, the communication problem is likely to be elsewhere on the network.
The error state is entered if the AIR XD has failed to set up the MODBUS TCP server. Power cycle the unit to retry the initialisation. If the unit is entering this state permanently/frequently, please contact Trolex Support.
If the AIR XD is in the offline state, check the connection of the Ethernet cables and power to any network switches or DHCP servers (if using DHCP)
6.2 Checking Connection with AIR XD
Communication to the AIR XD can be tested without running a MODBUS TCP client and instead
using the windows command line. Once the AIR XD is reporting an IP address either using DHCP or Static IP, open the command line and enter the command ‘ping’ followed by the IP address of the instrument. If the device can communicate on the network, then the terminal shall receive a reply as shown below:
6.3 Cannot communicate with terminal/laptop
If the ping command fails to return a response (timeout). Then perform the following checks to the network:
6.4 Cannot communicate on network also running DHCP server
If using dynamic IP allocation, check firewall settings to ensure communication is allowed on Port 502.
If using static IP assignment, check that no other device is allocated the same IP address of the instrument.