LS Industrial Systems GLOFA GM7U Series - Page 236

Chapter 8. Communication Functions
8-10
(3) GM7U basic unit response format (ACK response)
Format name Header
Station
No.
Command
Command
type
Number
of blocks
Device
length
Device name Tail
Frame
check
Frame ACK H20 R(r) SS H01 H02 HA9F3
...
ETX BCC
ASCII value H06 H3230 H52(72) H5353 H3031 H3032 H41394633 H04
1 block (max. 16 blocks possible)
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
data
Number of data means byte number of HEX type, and is converted into ASCII. This number is
determined according to data type (X,B,W,D) included in device name of computer request
Format.
• Number of data in accordance with its data type is as follows:
Data
In data area, there are the values of HEX data converted to ASCII code saved.
Frame check
(BCC)
When the command is lowercase(r), only one lower byte of the value resulted by adding 1 Byte
each to the ASCII values from ACK to ETX is converted into ASCII and added to BCC, and then
sent.
• The number of data and an example of using data
- The number of data is H04 (ASCII code value: H3034) means that there is HEX data of 4 bytes in data. Hex data of 4 bytes is
converted into ASCII code in data.
If number of data is H04 and the data is H12345678, ASCII code converted value of this is "31 32 33 34 35 36 37 38," and this
contents is entered in data area. Name directly, highest value is entered first, lowest value last.
- If data type is BOOL, data read is indicated by bytes. Namely, if bit value is 0, it indicated by H00 (ASCII: 30 30), and if 1, by
H01 (ASCII: 30 31).
Data type Available variable Number of data
BOOL(X) %MX,%QX,%IX 1
Byte(B) %MB,%QB,%IB 1
Word(W) %MW,%QW,%IW 2
Double Word(D) %MD,%QD,%ID 4
REMARK