DVP - ES2/EX2/SS2/SA2/SX2/SE Operation Manual - Programming

COM2 sends the function code of reading(K2/K3), the registers from S directly receive the data string and stored the converted data in D1296~D1311. Please refer to program example 1 and 3 for further explanation. When COM1 or COM3 sends the function code of reading(K2/K3), the registers store the converted data directly. Refer to program example 2 and 4 for further explanations.

6.n: Data length for accessing.

z When S2 (MODBUS function code) is specified as H05 which designates the PLC force ON/OFF status, n = 0 indicates ON and n = 1 indicates OFF.

z When S2 is specified as H02, H03, H0F, H10 which designate the data length for accessing, the available set range will be K1~Km, where m value should be specified according to communication modes and COM ports as the table below. (H02/H0F, unit: Bit. H03/H10, unit: Word.)

COM. mode

COM

H02

H03

H0F

H10

 

COM1

K 64

K 16

K 64

K 16

RTU

 

 

 

 

 

COM2

K 64

K 16

K 64

K 16

 

 

 

 

 

 

 

COM3

K 64

K 16

K 64

K 16

 

 

 

 

 

 

 

COM1

K 64

K 16

K 64

K 16

ASCII

 

 

 

 

 

COM2

K 64

K 8

K 64

K 8

 

 

 

 

 

 

 

COM3

K 64

K 16

K 64

K 16

 

 

 

 

 

 

7.There is no limitation on the times of using this instruction, however only one instruction can be executed on the same COM port at a time.

8.Rising-edge contact (LDP, ANDP, ORP) and falling-edge contact (LDF, ANDF, ORF) can not be used as drive contact of MODRW (Function code H02, H03) instruction, otherwise the data stored in the receiving registers will be incorrect.

9.If rising-edge contacts (LDP, ANDP, ORP) or falling-edge contacts (LDF, ANDF, ORF) is used before MODWR instruction, sending request flag M1122(COM2) / M1312(COM1) / M1316(COM3) has to be executed as a requirement.

10.MODRW instruction determines the COM port according to the communication request. The COM port determination is made following the order: COM1ÆCOM3ÆCOM2. Therefore, please insert every MODRW instruction right after the sending request instruction for avoiding errors on the target location for data access.

11.For detailed explanation of the associated flags and special registers, please refer to Points to note of API 80 RS instruction.

Program Example 1: COM2(RS-485), Function Code H02

1.Function code K2 (H02): read multiple bit devices, up to 64 bits can be read..

2.PLC1 connects to PLC2: (M1143 = OFF, ASCII mode), (M1143 = ON, RTU Mode)

3 - 332

Page 448
Image 448
Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual Com, H0F, COM1 RTU COM2 COM3 Ascii, Program Example 1 COM2RS-485, Function Code H02