Delta DVP-ES2 User Manual
Page 384
D V P - E S 2 / E X 2 / S S 2 / S A2 / S X 2 / S E O p e r a t i o n M a n u a l - P r o g r a m m i n g
3-268
API Mnemonic
Operands
Function
100
MODRD
Read Modbus Data
Controllers
ES2/EX2 SS2 SA2
SE
SX2
Bit Devices
Word devices
Program Steps
Type
OP
X Y M S K H
KnX
KnY KnM KnS T C D E F
S
1
*
*
*
S
2
*
*
*
n
*
*
*
MODRD: 7 steps
PULSE 16-bit 32-bit
ES2/EX2 SS2
SA2
SE
SX2 ES2/EX2 SS2
SA2
SE
SX2 ES2/EX2 SS2
SA2
SE
SX2
Operands:
S
1
: Device address (K0~K254) S
2
: 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 S
2
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.