ICP DAS, ZT-257x DIO Data Concentrator Quick Start Guide, v1.0
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Copyright © 2016, by ICP DAS Co., LTD. All Rights Reserved
5.2
Advanced functions: Status Detection Schemes in
Wireless Environments
The main principle for monitoring the I/O channels on the ZT-IOG system is to use the ZigBee
Coordinator module as a logical I/O coordinator that is responsible for synchronizing the
status of the DIO channels. This allows an I/O pair-connection function to be implemented
without the need to use additional PC/PAC devices. However, if any of the wireless devices
suffers a malfunction, or is disconnected, the Host will be unable to transmit a warning
message or take any appropriate action to resolve the issue.
To overcome this, two mechanisms are available on ZT-IOG series modules that can be
implemented to provide notifications when wireless communication is interrupted.
①
The Check-Router-Alive function
②
The Safe Value function
5.2.1.
The Check-Router-Alive function
The
Check-Router-Alive
function provided on the ZigBee Coordinator allows the status of the
connection between the ZigBee Router and the ZigBee Coordinator to be automatically
detected at a rate of one module per second. Details of the connection status will then be sent
to an external Host PC or PAC via either the Modbus RTU or TCP protocol.
-
For a ZT-20xx-IOG module (being used as a ZigBee Coordinator)
The ZT-20xx-IOG module provides a DO channel that can be used as a Disconnection Alarm
Channel. If the connection to any ZigBee Router on the network is interrupted, the
Disconnection Alarm Channel
(DO channel) will
immediately be active. In addition, an alarm
device (e.g., a buzzer or a warning light, etc.) can be connected to this DO channel on the
ZT-20xx-IOG module so that an alert will be triggered if the module is disconnected, thereby
allowing the on-site staff to be notified in order to prevent unexpected hazards while the
wireless communications are interrupted.
