Yokogawa YFGW710 - Manual (Page 79)

<B1. Engineering>
B1-15
IM 01W01F01-01EN
n Defining Process Data Communication
Define the transfer period and transfer destination (YFGW710 for this system) for each piece of
data of the field wireless device.
Table B1-9 Setting Parameters for Defining Process Data Communication
Parameter name Setting value Remark
Sampling Parameters Specify the field wireless device data to notify
to YFGW710.
By default, the process data of the field wire-
less device is specified.
The following three types can be set to
Sampling Parameters.
Unless all parameters are set, the field
wireless device will not transmit any data.
PV
PV_B
DAIG_STATUS
Update Policy Change is not necessary.
Periodic and Change of State can be set.
Always specify Periodic.
Change of State is a method to notify only
when data is changed.
Periodic is a method to notify of data at a
period specified in Publication Period.
Always specify Periodic for this system.
Publication Period Change the period if necessary.
The range is from 1 to 60 seconds.
5 seconds by default.
When 0 second is specified, no data is
notified from the field wireless device.
Stale Limit Time Change the time if necessary.
The range is from 10 to 255 seconds.
50 seconds by default.
Set a value that is larger than the publication
period.
When this specified time is exceeded and
data cannot be received from the field
wireless device, YFGW710 considers that
a communication error has occurred.
Destination for data The device tag of the communication destina-
tion is set.
Always point to YFGW710.
Change is not necessary.
l Publication Period and Stale Limit Time
• Publication Period
A publication period refers to a period at which the process data is notified to YFGW710
from the field wireless device.
Determine the publication period considering battery power consumption (which varies
depending on the publication period) or other factors.
• Stale Limit Time
The check process of wireless communication, the operating environment of the system,
deterioration of wireless quality, and communication path error and restoration may cause
data loss, retransmission of the same data, or variations in the data update time.
When the state of not-updated-data or lost-data continues for the period specified in Stale
Limit Time, YFGW710 considers that an error has occurred and notifies the control system
of an error.
Be sure to set a value that is larger than the publication period. It is recommended to set a value
10 times as large as the publication period. However, determine the value considering the fact
that the time from when the state of data-not-updated or data-lost occurs until the determination
of an error varies depending on the system environment and user application.