RIEVTECH PLC Manual BACnet RS 485MSTP EN (EN)

Rievtech PLC BACnet MSTP parameter configuration method and usage examples NOTE: (1)Ethernet PLC with firmware version number >=V1.57 supports BACnet. (2) Only xLogic with version number >=V3.4.3.7 supports BACnet. 1. Set PLC BACnet MSTP Open the BACnet configuration window, as shown in the figure below: Select the check box, the 'Config' button becomes available, then click this button, the configuration window pops up, as shown in the figure below. Divided into 3 pages: 'Comm', 'Object(BV)' and 'Object(AV)', the following three pages are introduced respectively.

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‘Comm’ page ‘Protocol’ Select BACnet protocol, there are 2 options: 'Bacnet MSTP' for RS485 communication and 'Bacnet IP' for Ethernet communication. Here select 'Bacnet MSTP'. ‘ Time out’ A value from 1 -- 30 (Second) can be set. ‘ Device number’ A value from 1 to 41943303 can be set, and its uniqueness needs to be guaranteed. ‘ Channel’ Select the RS485 channel supported by the PLC. The number of RS485 channels supported by different models is also different. The distribution of com ports on the PLC is shown in the figure below, taking PR-26DC-DAI-RT-N as an example:

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‘BPS’ Set the baud rate for RS485 communication. Different coms have different baud rate options. The default baud rate of PLC is 9600. ‘Parity’ There are three options: None, Odd, and Even, and the PLC defaults to None. ‘ PLC BACNET MAC’ It is necessary to ensure that the MAC of each device is unique, and a value from 0 to 127 can be set. ‘ BACNET MAC MAX’ The default value is 127, which sets the maximum mac value of BACnet devices in the network. The input range is 0 --127. Set the appropriate value according to the requirement. ‘Object(BV)’ page 16 digital objects can be set on this page, and an I, Q or F register can be assigned to each object.

Registers of type 'I' can only be read, not written. Registers of type 'Q' and 'F' support read/write. But in the program in the PLC, the input pins of their blocks need to be suspended, so that the write operation can be successful. First select 'Binary Value, 0' in the list on the left, set the name of the object on the right, and assign a register to it. 'Name' only allows up to 8 commonly used characters. ‘Object(AV)’ page

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Similarly, 16 analog objects can be set on this page, and an AI, AQ, AF or VW register can be assigned to each object. The 'AI' register can only read values, but cannot write values. AQ, AF and VW support read/write, and only when the input pins of these register blocks are floating, the write value operation can be successful. The operation steps are the same as the BV page. ‘Register data type’ The byte order when providing the value in register, you can choose 'HI-LO' and 'LO-HI' modes. ‘ DWORD data type’ The byte order of DWORD data, you can choose 'HI-LO' and 'LO-HI' modes. ‘ Display type’ Select the data format when displaying values, only support 'FLOAT'.

After configuring all the parameters, click the 'OK' button in the lower right corner, as shown in the figure below. Then download the BACnet settings to the PLC along with the xLogic program, and the settings will take effect after the PLC restarts.

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