Gx Works2 (Q-Cpu) Simple Ladder Acyclic Communication Example; Reading A Parameter (Sequence 1) - HMS A8NDPV1 Instruction Manual

GX Works2 (Q-CPU) Simple Ladder Acyclic communication example

3.9 GX Works2 (Q-CPU) Simple Ladder Acyclic
communication example
This chapter describes using acyclic communication through the A8NDPV1 Profibus option card
using GX Works 2 in Simple Ladder mode with a QCPU and QJ71PB92V Profibus Master. It con-
tains examples of reading and writing individual parameters. First perform the setup using tele-
gram 1. For additional information refer to the QJ71PB92V manual.
The process of acyclic communication parameter read consists of a write request, and a response
read. For details please refer to the Acyclic Data Exchange subchapter 7.7.
3.9.1

Reading a parameter (Sequence 1)

Creating the request
The first part of the program should read the acceptance/completion status of the acyclic re-
quest. This can be done with the following code:
Prepare the content for the parameter read request. The data request has the following format:
Byte no.
0
1
2
3
4
5
6-7
54
Description
Request ID
Request reference
No. of parameters
DO-ID
No. of elements
Attribute value
Parameter number
Get Started
Value
0x01
0x01-0xFF
0x01
0x01
0x00
0x10 (value attribute)
Byte swapped PNU
Doc.Id. HMSI-216-127
Doc.Rev. 1.01