User`s manual

AX2200/AX2300 Instruction Manual Chapter 4 Serial Communications
CM2-AX2000-2001 (Rev.4, 4/2014) 4-23
BACnet MS/TP Communications
1. BACnetMS/TPDescription
The BACnet Master-Slave/Token-Passing (MSTP) driver
implements a data link protocol that uses the services of the RS-
485 physical layer. The MS/TP bus is based on BACnet standard
protocol SSPC-135, Clause 9. BACnet MS/TP protocol is a peer-
to-peer, multiple master protocols based on token passing. Only
master devices can receive the token, and only the device holding
the token is allowed to originate a message on the bus. The token is
passed from master device to master device using a small message.
The token is passed in consecutive order starting with the lowest
address. Slave devices on the bus only communicate on the bus
when responding to a data request from a master device.
2. BaudRatesontheMS/TPBus
An MS/TP bus can be configured to communicate at one of four
different baud rates. It is very important that all of the devices on
an MS/TP bus communicate at the same baud rate. The baud rate
setting determines the rate at which devices communicate data
over the bus. The baud rate settings available on AX2000™
Vortex Mass Flow Meters are 9600, 19200 and 38400.
2.1. BaudRateandMACaddressconfiguration
1. PowerontheIUT
2. PressEntertogoconfigurationmenu
3. Givethe factorypassword16363(UseUpandDownarrowsto enter
thedigits)
4. NavigatetoDiagnosticsmenu
5. PressEnterandpressrightbuttonimmediately
6. NavigatetoConfigCodescreenbycontinuouspressingdownbutton
7. After reaching config code screen, press right to navigate to Comm. 
Typescreen
8. Changethecomm.Typeto“Modbus”
andpressEnter
Note:ModbuswillenableBaudRateandMACaddressscreens
9. PressExittwicetoreachDiagnosticsmenuback
10. Navigate toOutputMenubyusingrightorleftarrowbuttons
11. PressDownbuttonandreachBaudRateandMACaddressscreens