ProSoft Technology 5201-DFNT-DNPS - Manual (Page 67)

Reference ProLinx DNPS ♦ ProLinx Gateway
User Manual DNP 3.0 Slave
ProSoft Technology, Inc.
Page 67 of 86
December 1, 2009
Bit Description
6 Device trouble. When this bit is set, the data reported by the module may not be that
currently present in the other protocol because the block transfer operation is not
successful.
7 Device restart. This bit is set when the slave either warm or cold boots. It is cleared after
a master writes a 0 to the bit.
3.6.2 Second Byte
Bit Description
0 Bad function code. The function code contained in the master request is not supported for
the specified object/variation.
1 Requested object(s) unknown. Object requested by master is not supported by the
application.
2 Parameters in the qualifier, range, or data fields are not valid or out of range for the slave.
3 Event buffer(s) or other application buffers have overflowed. This bit is also set if the slave
receives a multi-frame message from the master.
4 Request understood but requested operation is already executing. The slave will never set
this bit.
5 Bad configuration. The slave configuration is invalid and should be re-configured. If the
configuration is invalid, the slave will set the invalid parameters to default values and
continue to run. Check error log using debug port.
6 Reserved, always 0.
7 Reserved, always 0.
3.7 Event Size Computation
The minimum event buffer size required to avoid overflow can be computed as
follows:
((number of static points)*(rate per second scan of change function)) /(rate
per second of master event data poll)
For example: 51 binary input points are scanned two times each second and
polled by the master station about every five seconds. The minimum number of
binary input events is:
(51 * 2)/.02 = 510 events
This computation assumes the unlikely event that all data points will change in
consecutive calls to the scan of change function. If an event buffer overflow
condition occurs, the internal indication bit, BUFFER OVERFLOW, will be set. If
the system you are working with is fairly stable, the following equation can be
used to compute the event buffer size:
(number of points that change per change function * rate per second of scan of
change function)*(number of seconds between master event data poll)
For example: 1000 binary input points are scanned two times each second and
polled by the master station about every five seconds. Only about five points
change state every scan of the change function call.
(5 * 2) * 5 = 50 events required