FUNCTION CODE CONFIGURATION
FUNCTION CODES
4 - 4
WBPEEUI240759A0
®
•
Each EDI module transaction message can contain a maxi-
mum of 243 bytes of information. This equates to the fol-
lowing for a single transaction:
58 float values.
116 integer values.
1,856 boolean values.
•
The PLC turn-around time, which refers to the time inter-
val between a request received from the EDI module and a
reply to the request, varies dependent on data type and can
range from approximately 20 milliseconds for digital values
up to approximately 150 milliseconds for some analog val-
ues.
•
To insure that a variable is updated at its desired scan rate
(i.e., 125 milliseconds, 250, milliseconds, 500 milliseconds,
and one second), the maximum number of transactions per
second should not exceed 160. For example, this equates
to:
20 transactions at 125 millisecond scan class (eight times
per second).
40 transactions at 250 millisecond scan class (four time
per second).
80 transactions at 500 milliseconds scan class (two times
per second).
160 transactions at one second scan class.
NOTE: Any combination can be used as long as the 160 maximum
is not exceeded.
The 160 transactions per second rate allows for a transfer
of:
9,280 float values per second.
18,560 integer values per second.
296,960 boolean values per second.
Example
As an example based on the previous data, 58 floating point
values per transaction means that seven MFP function blocks
configured with function code 186 and grouped together can
be updated in a single transaction.
Data Output Options
The MFP module (i.e., output subscriber function codes) can be
configured for either aperiodic or periodic data output opera-
tion. Aperiodic means data will only be sent to the PLC on an
MFP module exception basis (i.e., periodically, after reaching
