Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual Read Modbus Data

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

API

100

Mnemonic	Operands	Function	Controllers
MODRD		Read Modbus Data	ES2/EX2	SS2	SA2 SX2
					SE

Type

Bit Devices

Word devices

Program Steps

OP

X

Y

M

S

K

H

KnX

KnY

KnM

KnS

T

C

D

E

F

MODRD: 7 steps

S1

*

*

*

S2

*

*

*

n

*

*

*

PULSE

16-bit

32-bit

ES2/EX2

SS2

SA2

SX2

ES2/EX2

SS2

SA2

SX2

ES2/EX2

SS2

SA2

SX2

SE

SE

SE

Operands:

S1: Device address (K0~K254)

S2: Data address n: Data length (K1＜n≦K6)

Explanations:

1.MODRD instruction supports COM2 (RS-485).

2.MODRD is an instruction exclusively for peripheral communication equipment in MODBUS ASCII/RTU mode. The built-in RS-485 communication ports in Delta VFD drives (except for VFD-A series) are all compatible with MODBUS communication format. MODRD can be used for communication (read data) of Delta drives.

3.If the address of S2 is illegal for the designated communication device, the device will respond with an error, PLC will record the error code in D1130 and M1141 will be ON.

4.The feedback (returned) data from the peripheral equipment will be stored in D1070 ~ D1085. After data receiving is completed, PLC will check the validity of the data automatically. If there is an error, M1140 will be ON.

5.The feedback data are all ASCII codes in ASCII mode, so PLC will convert the feedback data into hex data and store them in D1050 ~ D1055. D1050 ~ D1055 is invalid in RTU mode.

6.If peripheral device receives a correct record (data) from PLC after M1140/M1141 = ON, the peripheral device will send out feedback data and PLC will reset M1140/M1141 after the validity of data is confirmed.

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

8.Rising-edge contact (LDP, ANDP, ORP) and falling-edge contact (LDF, ANDF, ORF) can not be used with MODRD instruction, otherwise the data stored in the receiving registers will be incorrect.

9.For associated flags and special registers, please refer to Points to note of API 80 RS instruction.

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