Momentum Sales & Marketing 170 PNT Series Configuration Registers, Module Timeout, Parameters

Communication Access Registers

Configuration Registers

Overview	This section describes the function and parameters for module timeout and module
	ownership registers.
Module Timeout
	The module timeout register specifies the amount of time that outputs will be held in
Register	their current state, if they are not updated by a new Modbus Plus Write command.
Function	If the module’s holdup time expires before a new write command is received, all
	outputs are set to logical 0 (zero).
Module Timeout
	The table below gives the parameters for module timeout registers:
Register
	Parameters
Parameters
	Sharing Reference	4F001 (hex)
	Field Length	1 word
	Access	Modbus Plus Read command
	Units	1 = 10 milliseconds
	Minimum Value	30 (300 milliseconds)
	Maximum Value	6000 (60 seconds)
	Default Value	100 (1 second)

Module

Ownership

Registers

Function

Module ownership registers specify the addresses of up to three nodes which may concurrently own write privilege to the adapter.

When the adapter first receives power, it will give sole write privilege to the first node that writes to it. The adapter maintains an internal 60-second timer for handling the write privilege, and will reserve sole privilege to that node as long at the node continues to write within 60-second intervals to the adapter.

A node which currently owns the write privilege may write up to three words to the adapter starting at reference 4F401. Each of the three words must correspond to a valid node address in the range 1...64 decimal. With those addresses stored in the adapter, any of those three nodes may then write to the adapter. This allows up to three nodes to concurrently own write privilege to the adapter.

If writes continue to occur within the 60-second interval from any of the three privileged nodes, no other node may write to the adapter. If the timer is allowed to expire, any node may write to the adapter.

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