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F-1500 Turbine Flow Meter Manual 02/18 - 1018-6 / 35726
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4.3 BACnet MS/TP Communications
4.3.1. 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.
4.3.2. 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 available baud rate settings available on F-1500 Flow Meters are 9600, 19200 ,
38400 and 76800.
4.3.2.1. Baud Rate and MAC address configuration
1. Power on the meter
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
12. Change the required settings and press Exit & Enter buttons to save the
configuration
13. Do steps from b to g, and change the comm. Type as Hart.
14. Reboot the device by power off and on.
Note:
a. Baud rates are 9600, 19200, 38400 or 76800
b. MAC address range is 0-127
4.3.3. Supported BACnet Objects
A BACnet object represents physical or virtual equipment information, as a digital input
or parameters. ONICON F-1500 Flow Meters present the following object types:
a. Device Object
b. Analog Input
c. Binary Input
d. Binary Value
Each object type defines a data structure composed by properties that allow the access to
the object information. The below table shows the implemented properties for each Mass
Flow Meters object type.