Delta VP3000 Series - Page 344

Chapter 7 Second Development PlatformVP3000
335
API Instruction code Operand Function
150 MODRW S
1
, S
2
, S
3
, S, n
Read / write Modbus data
Type
Operand
Bit devices Word devices
16-bit instruction (11 steps)
MODRW
C
ontinuous
execution
type
MODRWP
Pulse
execution
type
32-bit instruction
- - - -
Associated flag: M1077, M1078, M1079,
M1080, M1081
X Y M K H KnX KnY KnM T C D
S
1
  
S
2
  
S
3
  
S

n
  
Caution for using operand
 Since the communication process goes through PLC scan for many
times, it is recommended to use the pulse execution type of this
function code.
Description
 S
1
: address of communication device
S
2
: function code
S
3
: device address of data to be read / written
S: register for storing read / written data
n: length of read / written data
 Before using this instruction, COM1 must be defined as being controlled by PLC (set Pr.N1-07 =
1). After that, set the corresponding communication speed and format (Pr.N1-02 and Pr.N1-03).
For function code (S
2
), only these function codes listed below are available currently, others are
still not executable.
Function Description
H02 Read multiple coil (bit)
H03 Read multiple word
H06 Write single word
H0F Write multiple coil (bit)
H10 Write multiple word

A
fter the instruction is executed, M1077, M1078, M1079, M1080 and M1081 becomes 0
immediately.
 For example, if you want the PLC master of the drive to control another drive slave and PLC
slave, assume the station number of drive slave is 10, and the one of PLC slave is 20. See
explanation below:
The drive to control slave devices
No. Example
MODRW Instruction
S
1
S
2
S
3
S n
Station
number
Command
code
Address Register Length
1
Read the parameters Pr.A0-00–Pr.A0-03
of drive slave, 4 records in total. And
store the data to D0–D3.
K10 H3 H0000 D0 K4