Block read sizes: unsolicited block read mode
Data type | PLC-5 | PLC-3 | SLC 500 | SLC 5/03c or SLC 5/04 |
|---|---|---|---|---|
Bytes per packet | 200 | 100 | ||
Binary | 100 | 50 | 40 | 100 |
ASCII | 100 | 50 | 100 | |
Outputs | 100 | 50 | ||
Inputs | 100 | 50 | ||
Status | 100 | 50 | 40 | 100 |
Integer | 100 | 50 | 40 | 100 |
Timer | 33 | 16 | 13 | 33 |
Counter | 33 | 16 | 13 | 33 |
Control | 33 | 13 | 33 | |
Floating Point | 50 | 25 | 50 | |
BCD | 100 | 50 | ||
High-order Integer | 25 | |||
String | ||||
Pointer | 25 |
The following are some special considerations for specific processors.
PLC-5 unsolicited message mode
RSLinx Classic calculates all block read sizes based on the capacity to move up to 180 bytes of data in a single packet. For example, B3:0,L90 reads 90 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.
PLC-2 unsolicited message mode
RSLinx Classic calculates all block read sizes based on the capacity to move up to 200 bytes of data in a single packet. Since there is only a single data type within the PLC-2, all requests can be for a maximum of 100 words of data.
SLC 500 unsolicited message mode
Unsolicited messages are supported for the SLC 500.
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