LV5V-2RS485 BD Board Manual V1.0
6 WECON technology Co., Ltd
7 to 8 digits.
Stop bit: Indicates the number of stop bits in serial communication, and the value range is
1 to 2 digits.
Parity bit: Indicates whether to add check bits during serial communication, and check
types. Odd check and even check are commonly used.
Timeout (10ms): Configuration for the master station, indicating the maximum waiting
time between the request and the reply. The unit is 10ms, and the configuration here is 10,
which means 10*10ms=100ms.
Sending interval (0.1 ms): Configuration for the master station, indicating the time when
the communication is completed and the next request is sent.
Agreement: Currently supported protocols are: user-defined protocol, dedicated protocol,
Modbus RTU, Modbus ASCII.
User-defined protocol: Users need to organize request frames by themselves, and
process response frames after receiving response data.
Dedicated protocol: WECON Modbus protocol (PLC local protocol) is used for program
upload and download, HMI monitoring protocol.
(3) Agreement related:
Station NO. (0 is the main station): The value range is 0 to 255. Non-0 indicates the slave
station number, and 0 indicates the master station.
Whether to enable the starter: Effective under user-defined protocol. When enabled, a
user-defined starter of one-byte is sent first before sending user data.
Whether to enable the terminator: Effective under user-defined protocol. When enabled,
a user-defined terminator of one-byte is sent again after the user data is sent.
(4) Terminator: Effective under user-defined protocol.
(5) Inter-character timeout (0.1 ms): Mainly used to judge whether a complete response frame is
received. After receiving a byte, if there is no new byte is received beyond the time-out interval
between characters, it indicates that the data of the previous frame has been received.
(6) Bit mode: It is divided into 8-bit and 16-bit modes, which are mainly used to define the storage
mode of data received by user-defined protocol. Assume that the user-defined protocol
receives two bytes of data, 0x12 and 0x13, and stores them in the device starting with D100.
The storage mode of 16-bit mode is as follows:
The storage mode of 8-bit mode is as follows:
5 RS2 instruction
In the case of user-defined protocol: The instruction is a communication receiving and sending
instruction. The starting data of the specified (S) is taken out (M) and sent, and the data received by
the serial port is stored in (D), and store (N), sent by the communication port specified by (N1).
In the case of Modbus master protocol: The instruction is a setting interface for sending protocol
frames by the master station. According to the station number function code (S), slave station
address (M), and length (D) set by the instruction, and the function code to determine whether N
data is needed to automatically combine to send and receive protocol frames. If it is a read type
