DTI420 DTI421
21
u
Use the control to set the following values in the process data output: the command value "0x03",
the address (16 bits) and the data length (16 bits).
u
With the control, start the read operation with the status bit "Cmd Start”.
w
The device acknowledges the start of the read operation by setting the status bit "Cmd Start
Acknowledge" in the process data input.
w
The device transfers the data in the process data input (data 0 to 27) and increases the block
counter by 1 as soon as the first data of the ID tag is available. The block counter is reset to “0”
when the value exceeds “255”.
u
With the control, acknowledge the receipt of the data by increasing the block counter in the process
data output by “1”.
u
The last two steps are repeated until all data has been transferred.
w
The device sets the status bit "Cmd End" with the last transfer.
The read operation is terminated.
If reading was unsuccessful, the device sets the error value and the status bit "Cmd End" in the
process image. The data transmission is interrupted.
Byte
Process data output
Process data input
0
Command value = 0x03
Command value = 0x03
1
Status
Status
2
ignored
Data 0
3
ignored
Data 1
4
Address (high byte)
Data 2
5
Address (low byte)
Data 3
6
Length (high byte)
Data 4
7
Length (low byte)
Data 5
8
ignored
Data 6
9
ignored
Data 7
10
ignored
Data 8
11
ignored
Data 9
12
ignored
Data 10
13
ignored
Data 11
14
ignored
Data 12
15
ignored
Data 13
16
ignored
Data 14
17
ignored
Data 15
18
ignored
Data 16
19
ignored
Data 17
20
ignored
Data 18
21
ignored
Data 19
22
ignored
Data 20
23
ignored
Data 21
24
ignored
Data 22
25
ignored
Data 23
26
ignored
Data 24
27
ignored
Data 25
