Block read sizes: polled block read mode

Data type
PLC-5
SLC 500
SLC 5/03c or SLC 5/04
Binary
100
40
100
ASCII
100
100
Outputs
100
100
Inputs
100
100
Status
100
40
100
Integer
100
40
100
Timer
33
13
33
Counter
33
13
33
Control
33
13
33
Floating Point
50
50
BCD
100
100
High-order Integer
String
2
2
Pointer
The following are some special considerations for specific processors.
PLC-5 polled block read mode
RSLinx Classic calculates all block read sizes based on the capacity to move up to 100 words of data in a single packet. For example, B3:0,L100 reads 100 words starting at element B3:0 and returns them as a series of unsigned integers. To return a binary string instead of an unsigned integer, use the B specifier.
The type of PLC-5 used and its current configuration determines the size of the input, output, and status files. For example, when accessing a PLC-5 via an Ethernet interface, all maximum sizes are multiplied by a factor of 10.
SLC 500 polled block read mode
RSLinx Classic calculates all block read sizes based on the capacity to move up to 40 words of data in a single packet. In the SLC 500 processor, you cannot read real I/O directly. You must write ladder logic to move your I/O values to integer or binary files for reading.
Provide Feedback
Have questions or feedback about this documentation? Please submit your feedback here.
Normal