YOKOGAWA VZ20X, Technical Information

Page: 28 / 55

TI 77V01B01-11EN Oct.18, 2021-00
3.2 Data Monitoring Procedure: Details of Data
Monitoring with Function Code 70/71
This section describes the flow of operations when
using exclusive function code 70/71 for data
monitoring.
With each data monitoring response, 4 ms of data
consisting of four sets of "date", "time", "measured
values for CH1 to CH8", and "measured value status
for CH1 to CH8" can be acquired.
Perform data monitoring by continuously repeating
communication with data monitoring function code
71.
The data buffer in VZ20X stores 8 channels x 2000
points of data. In the case of a 1 ms interval, 2
seconds of data for 8 channels is stored in the data
buffer. Acquire the data by performing
communication before the data buffer is overwritten.
Start
End
YES
YES
YES
Not yet buffered
Data omission
Data acquisition (normal)
NO
NO
NO
Function code: 70 (Data acquisition control)
Function selection: 0001 (Start data acquisition)
Function code: 71 (Data acquisition)
Function selection: 0001 (Acquisition of latest
data acquisition value)
Function code: 70 (Data acquisition control)
Function selection: 0002 (Stop data acquisition)
Data acquisition status
= 00 (normal)
Data acquisition status
= 01 (not yet bu ffered)
Continue data acquisition?
3.2 Data Monitoring Procedure: Overview of Monitoring
Measured Values
FC=70 Monitoring start request
FC=70 Monitoring start response
FC=71 Monitoring request
FC=71 Monitoring response
FC=71 Monitoring request
FC=71 Monitoring response
TIME DATE MES.VAL.1-8CH STATUS1-8CH
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
No.1
No.2
No.3
No.4
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
TIME
DATE MES.VAL.1-8CH
STATUS1-8CH
No.5
No.6
No.7
No.8
The same request is sent repeatedly when
monitoring with exclusive function code 71,
but four sets of the latest data can be
acquired in each response.
Example:
Data sets No. 1 to No. 4 can be acquired in
the first 71 monitoring response.
Data sets No. 5 to No. 8 can be acquired in
the second 71 monitoring response.
28