Rockwell Automation T8019 Trusted Process Control Algorithm Software Package - Manual (Page 7)

Trusted
TM
Process Control Algorithms T8019
Issue 8 Sep 07 PD-T8019 7
1. Description
Several of the basic control algorithms may generate error conditions at run-time as all function
parameters are variable. This may result in reversed parameters, e.g. max < min, overflow and
underflow conditions, divide by zero errors, etc. For each function, the required output under these
conditions is defined and error counters are incremented. These error counters are available to the
application programmer using the error statistics function block.
The function block has a single Boolean input that is used to reset the counters. Whilst this input is
true, the error counters will be reset to zero. The initial value of all error counters is zero.
ERRSTAT
RESET
Overflow
Param
Reversed
Zero Divide
Underflow
Data types are
1. RESET Boolean
2. All others Integer
Output Error condition
Reversed Pairs of function parameters are reversed, i.e. maxThe associated function has reversed the two values in order
to obtain a valid result. The count is incremented on each
iteration of the function whilst the parameters are reversed.
Param A function parameter is incorrect, e.g. out of range or not
consistent with the functions required operation. The count
is incremented on each iteration of the function whilst the
parameter is incorrect.
Overflow An overflow error occurred in the execution of the function.
The count is incremented on each iteration of the function
whilst the overflow condition occurs.
Underflow An underflow error occurred in the execution of the function.
The count is incremented on each iteration of the function
whilst the underflow condition occurs.
Zero Divide A divide by zero error occurred in the execution of the
function. The count is incremented on each iteration of the
function whilst the divide by zero condition occurs.
Table 1 Error Statistics