Chapter 8. Communication Functions
8-9
8.1.6 Command Execution
1) Individual reading of direct variable (R(r)SS)
(1)
Introduction
- This is a function that reads PLC device specified in accord with memory data type. Separate device memory can be read
up to 16 at a time.
(2)
PC request format
Format
name
Header
Station
No.
Command
Command
type
Number
of blocks
Device
length
Device name
Tail
Frame
check
Frame ENQ H10 R(r)
SS
H01 H06 %MW100
...
EOT
BCC
ASCII
value
H05 H3130 H52(72) H5353 H3031
H3036
H254D57313030 H04
Item
Description
Station No.
HEX value is displayed as ASCII 2 bytes in station.
The example above shows H10 that is the case when the station no. 16 of GM7U is requested
data.
Number of
blocks
This specifies how much of the blocks composed of "[device length][device name]" are in this
request format. This can be set up to 16. Therefore, the value of [Number of blocks] must be set
between H01 (ASCII value: 3031)-H10 (ASCII value: 3030).
Device length
This indicates the number of device name's characters, which is allowable up to 16 characters.
This value is one of ASCII converted from HEX type,
- If the device name is %MW0, it has 4 characters to be H04.
- If the device name is %QW0.0.0, it has 8 characters to be H08.
Device name
Address to be actually read is entered. This must be ASCII value within 16 characters, and in this
name, digits, upper/lower case, '%' only is allowable to be entered.
Frame check
(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.
Example) BCC of the above frame is obtained as below:
H05+H32+H30+H72+H53+H53+H30+H31+H30+H36+H25+H4D+H57+H31+H30+H30+H04
=H03A4
Therefore, BCC value A4 becomes H4134 (ASCII).
1)
‘H’ of example frame represents HEX value, and is unnecessary during preparing real frame.
2)
The device type for each block should be identical; otherwise an error will be occurred.
1 block (setting can be repeated up to max. 16 blocks)
REMARK
Summary of Contents for GLOFA G7M-DR20U
Page 28: ...Chapter 4 Names of Parts 4 3 2 G7M DRT60U N 3 G7M DT60U N 4 G7M DT60U P...
Page 29: ...Chapter 4 Names of Parts 4 4 5 G7M DR60U DC 6 G7M DRT60U N DC 7 G7M DT60U N DC...
Page 31: ...Chapter 4 Names of Parts 4 6 3 G7M DT40U N 4 G7M DT40U P 5 G7M DR40U DC...
Page 32: ...Chapter 4 Names of Parts 4 7 6 G7M DRT40U N DC 7 G7M DT40U N DC 8 G7M DT40U P DC...
Page 33: ...Chapter 4 Names of Parts 4 8 4 1 3 30 point main unit 1 G7M DR30U 2 G7M DRT30U N 3 G7M DT30U N...
Page 34: ...Chapter 4 Names of Parts 4 9 4 G7M DT30U P 5 G7M DR30U DC 6 G7M DRT30U N DC...
Page 36: ...Chapter 4 Names of Parts 4 11 2 G7M DRT20U N 3 G7M DT20U N 4 G7M DT20U P...
Page 37: ...Chapter 4 Names of Parts 4 12 5 G7M DR20U DC 6 G7M DRT20U N DC 7 G7M DT20U N DC...
Page 38: ...Chapter 4 Names of Parts 4 13 8 G7M DT20U P DC...
Page 159: ...Chapter 7 Usage of Various Functions 7 52 c Program...
Page 183: ...Chapter 7 Usage of Various Functions 7 76 c Program...
Page 253: ...Chapter 8 Communication Functions 8 27 b When uses Ch 1 Built in RS 485...
Page 356: ...Appendix 1 System Definitions App1 9 6 Position Parameter...
Page 357: ...Appendix 1 System Definitions App1 10 7 High Speed Counter Parameter...