Installation manual

Publication 1747-RM001G-EN-P - November 2008
Programming Instruction References D-21
TIP
Message lengths for SLC 5/05 processors are shown in the next table.
Message lengths are based on Ethernet buffer size of 2108 bytes (includes command
header and system addressing in addition to actual file data). The local file is the
destination file for reads and the source files for writes.
In the following table, byte values are the maximum byte length argument values the
compiler should generate to be passed to the MSG instruction and then written to word
11 of the MSG control block by the processor at run time.
Table D.5 SLC 5/05 Message Lengths
File
Type
485CIF and 500CPU Read/Write PLC5 Read PLC5 Write
Elements Bytes Elements Bytes Elements Bytes
O,I 256 512 256 512 256 512
S 83 166 83 166 83 166
B 256 512 256 512 256 512
T 256 1536 256 (208 when
target file type is
Timer)
1536 (1248 when
target file type is
Timer)
208 (201 when
using logical ASCII
addressing)
1248 (1206 when
using logical ASCII
addressing)
C 256 1536 256 1536 256 1536
R 256 1536 256 1536 256 1536
N 256 512 256 512 256 512
F 256 1024 256 1024 256 1024
A 256 512 - Treat an
ASCII file element
here as a whole
16-bit word.
256 512 - Treat an
ASCII file element
here as 1 byte like
PLCs do;
compensate by
doubling the
number of
elements that can
be read.
256 512 - Treat an
ASCII file element
here as 1 byte like
PLCs do;
compensate by
doubling the
number of
elements that can
be read.
ST 25 (24 for 500CPU
write)
2100 (2016 for
500CPU write)
11
M 256 512 256 512 256 512