Oldham WX16, User Manual

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WX16 User Manual | 24
The Mastr TO (master time out) and Mastr PR (master poll rate) menu items affect the
WX16’s master ModBus port. Time out sets length of time in milliseconds before a
communications error. Three consecutive timeout errors must occur before a
communication error is indicated. This item is useful for optimizing throughput to the
WX16 from other slave RTU’s.
Poll Rate sets frequency of data requests to the RTU’s
in milliseconds. This is useful when an RTU is limited in how fast it may respond to
consecutive data requests.
The Echo ACK (echo acknowledge) menu allows alarm reset / alarm acknowledge
functions be sent from the ModBus master port to connected ModBus slave devices
having ModBus coil 2001 assigned as the reset / acknowledge coil. This menu may be
set to
OFF , LCL (local) or MB/LCL (ModBus/local). Off disables the feature and 2001
coils of slave devices are unaffected. LCL only writes to the 2001 coils of connected
RTU’s when the local Reset pushbutton is pressed. MB/LCL writes these coils if this
WX16’s 2001 coil has been reset via mobus AND when the local pushbutton is
pressed. The
MB/LCL option is useful if WX16s are being cascaded from an HMI or
other ModBus master. A short time delay between reset of remote RTU’s and the
primary WX16 may occur, since remote resets are processed first.
IMPORTANT! ALL MODBUS 2001 COILS ARE WRITTEN BY THIS
FEATURE. DO NOT CONNECT DEVICES WITH 2001 COILS
CONTROLLING OTHER CRITICAL EVENTS!
2.3.4a Master Port Radio Setup Menu
The radio kit option may be connected to the comm1 master port and receive
wireless data transmissions from up to sixteen of Oldham’s OLCT 200
wireless sensor transmitters. It is not possible to also use the comm1
master
port to communicate to “wired” ModBus transmitters, and if any channels are set for
ModBus, they will report “comm. error”.
See Section 7 for a detailed discussion of WX16 wireless operation.
Figure 2.14