208 Creating and Running Algorithms Chapter 6
NOTE Identifiers are case sensitive. The names My_array and my_array reference
different variables.
Special Identifiersfor Channels
Channel identifiers appear as variable identifiers within the algorithm and
have a fixed, reserved syntax. The identifiers I100 to I163 specify on-board
input channel numbers. The identifiers I10000 toI15731 specify remote
input channel numbers. The "I" must be upper case. They may only appear
on the right side of an assignment operator. The identifiers O100 toO163
specify output channel numbers. The "O" must be upper case. They can
appear on either or both sides of the assignment operator.
Special Identifiersfor Remote ScanStatus
Remote Scan Status identifiers appear as variable identifiers within the
algorithm and have a fixed, reserved syntax. The identifiers S100, S101,
S108, S109, S116, S117, S124, S125, S132, S133, S140, S141, S148, S149,
S156 and S157 specify scan status variables that are linked to the on-board
channels of VT1539A SCPs. These VT1539A SCP channels are in turn
connected to Remote Signal Conditioning Units (RSCUs). The identifiers
are treated like input channel specifiers and may only appear on the right
side of an assignment operator. The "S" must be upper case.
When accessed, these identifiers return one of three values: 0=normal RSCU
operation, 1=RSCU cable disconnected after INIT and 2=RSCU scan is out
of synchronization (RSCU scan trigger problem during scan).
NOTE Trying to declare a variable with a channel or status identifier will generate
an error.
Operators The VT1422A's Algorithm Language supports the following operators:
Assignment Operator = (assignment) example; c = 1.2345
Arithmetic Operators + (addition) examples; c = a + b
- (subtraction) c = a - b
* (multiplication) c = a * b
/ (division) c = a / b
Unary Operators - (unary minus) c = a + (-b)
+ (unary plus) c = a + (+b)