Spirax Sarco RIM20, Инструкция по установке и обслуживанию, Страница: 91 / 132

IM-P198-05 MI Issue 2 91
5.7 BACnet MS/TP communications
The BACnet Master-Slave/Token-Passing (MS/TP) 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.
5.8 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 RIM20 Vortex Mass flowmeters are 9600, 19200, 38400,
57600 and 115200
5.8.1 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 Output menu
5. Navigate to Output Menu by using right or left arrow buttons
6. Press Down button and reach Baud Rate MAC address, and Device Instance screens
7. Change the required settings and press Exit & Enter buttons to save the configuration
8. Do steps from b to g, and change the comm. Type as Hart.
9. Reboot the device by power off and on.
Note:
a. IUT support 9600, 19200, 38400, 57600, 115200 baud rates
b. MAC address range is 0-127