Chapter8 Communication Function
8-13
2) Continuous reading(RSB) of device
(1) Introduction
This is a function that reads the PLC device memory directly specified in accord with memory data type.
With this, data is read from specified address as much as specified continuously.
(2) PC request format
Format name
Header
Station
No.
Command
Command
type
Device
length
Device
Number of data
(Max. 128 Bytes)
Tail
Frame
check
Ex. of frame
ENQ
H10
R(r)
SB
H06
%MW100
H05
EOT
BCC
ASCII value
H05
H3130
H52(72)
H5342
H3036
H254D57313030
H3035
H04
Remark
1)
Number of data specifies the number according to the type of data. Namely, if the data type of device is
word, and number is 5, it means that 5 WORDs should be read.
2)
Max. of %MW in number of data can be used up to 64.
3)
Protocol of RSB doesn't have number of blocks.
4)
R(r)SB command of bit devices is not available.
Item
Explanation
BCC
When command is lowercase(r), only one lower byte of the value resulted by adding 1 Byte
each to ASCII values from ENQ to EOT is converted into ASCII and added to BCC.
Device
length(Name
length of device)
This indicates the number of name's characters that means device, which is allowable up to
16 characters. This value is one of ASCII converted from hex type, and the range is from
H01(ASCII value:3031) to H10(ASCII value:3130).
Device name
Address to be actually read is entered. This must be ASCII value within 16 characters, and in
this name, digits, upper/lowercase, and '%' only are allowable to be entered.
