ProSoft Technology 5201-DFNT-104S - Manual (Page 21)

Configure the Gateway 104S v2 ♦ ProLinx Gateway
Protocol Manual (Firmware v2.xx)
ProSoft Technology, Inc.
Page 21 of 157
March 19, 2010
Cyclic Set IV Time
1 to 65535 seconds, or 0 to disable Invalid Bit Monitoring
The parameter should be set to a value significantly greater than the value of the
IV Check Delay Time parameter, multiplied by the value of the IV Fail Count
parameter. Example:
If, IV Check Delay = 3
And, IV Fail Count = 5;
Then set Cyclic Set IV Time significantly greater than 15; preferrably some
multiple of this value, like 30, 45, 60,
or more.
The Cyclic Set IV Time parameter is one of three parameters needed to establish
a fail-safe data validation system for this protocol implementaion. This parameter
is used with the IV Check Delay Time and the IV Fail Count parameters to create
a way to alert the remote IEC-104 Client to situations where data being sent by
the gateway might be invalid.
Use the Cyclic Set IV Time parameter to set how frequently the Invalid (IV) Bits
assigned to IEC database monitor points (M_xx_xx points) will be set ON. This
means that all the IEC database monitor points configured with IV Bit addresses
greater than zero (0) will have their IV Bit addresses in the gateway database set
to a value of one (1) in a timed, periodic cycle, based on the number of seconds
entered in Cyclic Set IV Time.
The IV Bits are checked at the interval specified by the IV Check Delay Time
parameter. At the end of each check delay interval, if an IV Bit for any IEC
database point is ON, an IV Bit Check Fail accumulator for that point will be
incremented. If the value in any IV Bit Check Fail accumulator becomes equal to
the value of the IV Fail Count parameter, the gateway will consider the data value
of that point invalid and will report the invalid status of that point to the Client
along with the data value.
If the IV Bit is cleared (reset, set OFF, set to zero) before the IV Bit Check Fail
accumulator value becomes equal to the value of the IV Fail Count parameter,
the IV Bit Check Fail accumulator will be reset to 0. The gateway will consider the
data value of that point valid and will report the data value to the Client as valid.
To properly use data validity checking with a ProLinx Gateway, the application
that communicates to the gateway through the other gateway protocol (Modbus,
EtherNet/IP, etc.) must be programmed to provide data validity information, as
well as the actual data to be transferred. This other application must write bit
values of zero (0) or one (1) to the proper gateway database addresses along
with the data for each IEC database point.
To properly use data validity checking with an inRAx rack-mounted module for
Rockwell Automation processor systems or with a ProTalkQ rack-mounted
module for Modicon Quantum processor systems, the logic application running in
the processor that communicates to the module through a backplane input/output
driver must be programmed to provide data validity information, as well as the
actual data to be transferred. This logic application must write bit values of zero
(0) or one (1) to the proper module database addresses along with the data for
each IEC database point.