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Configuration Extensions
114
372 SPU 780 01EMAN May 2002
Editing the Peer
Cop Extension
In the Active Extensions panel select the Peer Cop extension, then:
Global Input/
Output
Global I/O is one of two communication methods used by the Peer Cop extension
(the other is Specific I/O). Global I/O is a broadcast communication method, where
a message is broadcast (made available) to all controllers on the Modbus Plus
network. Global I/O data transfers do not require an acknowledgment from the
receiving controller, so there is no immediate overhead placed on the receiving
controller.
Step Action
1 The Peer Cop extension can be configured for up to three links. When you add
a link you will have access to the 64 possible devices on another peer-to-peer
network.
Link 1 is the internal link; all devices on the local Modbus Plus network can
be accessed from Link 1.
Links 2 and 3 are remote links through S985 cards.
To add a link, click Add Link. To clear the configuration of a link, click Clear
Link. To delete a link, click Delete Link.
2 To configure a link, set its Head Number, Time-out value, and Last Value
parameters.
For link 2 or 3, select a head number (1 through 16) from the Link x Head
Number drop-down list box. Head Number specifies the head number on a
Quantum rack. If you are using a Quantum Controller, you have the option of
editing the head number for the second or third link. The first link is internal,
therefore it cannot be edited.
3 Select a value from the Timeout (ms) drop-down list box. Time-out specifies the
health time-out interval. The default value is 500ms. This value specifies the
minimum time period a Peer Cop configured communication must fail before the
associated health bit is cleared. Valid time-out values range from 20ms to 2
seconds. If you type a value too big, the value truncates to a multiple of 20. For
example, 230 truncates to 220 (it is not rounded up to 240).
4 Select ‘Clear’ or ‘Hold’ from the Last Value drop-down list box. Last Value
specifies whether or not to hold the last value. When set to ‘Hold’, the input data
area associated with an unhealthy transfer is left in its previous state (i.e. the last
value with a health of OK).
Note: You can view the register data of any global input/output or specific input/
output by clicking View Data. The data watch window will open displaying the
relevant data.