Communications Commands and Responses
Section 5-3
5-11
5-3-4
Selective Access Commands and Responses
1)
Detection of Tags
Command for the use of detecting Tags in communications area.
Command Frame Structure
STX
Node No. Command
code
“RD”
Commu-
nications
Data
type
Tag
No.
setting
First read
page
No. of read
pages
ETX BCC
1
2
2
2
1
1
2
2
1
1
Communications
Specifies a communications method.
LT: Selective Access
For details, refer to 5-5 Communications Methods.
Data type
Specifies whether the read data is represented in ASCII or HEX.
A: ASCII code
H: HEX code
For details, refer to 5-6 Data Type.
First read page
Specifies the first page of the Tag containing data to be read in HEX.
Setting range: 00h to 0Ah, FFh
(FFh can be specified only when using Philips’ block 4 as user memory. For de-
tails, refer to 2-5 Tag Memory Map.)
No. of read pages
Specifies the number of pages to which data is written in HEX.
Setting range: 01h to 0Ch
Tag Number setting
Specifies the Tag Number setting.
Setting range: 1 to 7
For details, refer to 5-7 Tag Number Setting.
Response Frame Structure
·
Read data response
STX
Node No.
Retry
flag
Command
code
“RD”
Response
code
“00”
Temporary
No.
Read data
ETX BCC
1
2
1
2
2
2
Specified
number
1
1
·
Communications end response
STX
Node No.
Retry
flag
Command
code
“RD”
Response
code
“72”
ETX BCC
1
2
1
2
2
1
1
Response code
00: Normal completion
72:Detection response
For other response codes, refer to 5-10 Response Code List.
Read data
Indicates the data having been read. The number of characters of the data is as fol-
lows:
ASCII code: No. of read pages x 4
HEX code: No. of read pages x 8
Temporary No.
As a normal response, the values 00 to 7F are returned.
