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Communications Time
Section 7-1
7-3
2) Fast mode
1
0
2
0
4
0
6
0
8
0
1
0
0
1
2
0
1
4
0
1
8
0
T
A
T
(
m
s
)
Number of pages processed
2
3
4
5
6
7
8
9
1
0
1
1
1
6
0
Writing
Reading
Special reading
1
0
2
0
4
0
6
0
8
0
1
0
0
1
2
0
1
4
0
1
8
0
Actual
communicat
ions time
(ms)
Number of pages processed
2
3
4
5
6
7
8
9
1
0
1
1
1
6
0
Writing
Reading
Special reading
Calculation Formula
(msec)
Actual communications time (ms)
Special reading
T = 1.3N + 6.2
Read
T = 1.3N + 12.7
Write
T = 13N +13.5
N: Number of pages processed
Note
•
The provided TAT graph data shows an example in which the
V720S-BC5D4 Controller is used with the following communications
specifications for host communications: The data is continuously sent with
no space between characters, at a baud rate of 38,400 bps, in a data length
of 7 bits with 1 start bit, 2 stop bits and even parity.
•
The number of bytes in TAT data is the number of code-specified bytes in
ASCII.
3) Actual Communications Time in Multiple, Simultaneous Access Mode
The actual communications time between the Controller and Tag using commands for multiple access
varies with the operating conditions, such as the number of Tags in the communications area as well
as the number of bytes to be processed.
Refer to the following table for standard values in consideration of these conditions.
(msec)
2 pages (8 bytes) to read (ms)
2 pages (8 bytes) to write (ms)
Number of
Tags
Timeslot setting
Standard mode
Fast mode
Standard mode
Fast mode
2
1
560
144
715
190
4
2
917
301
1139
378
8
3
1659
644
2016
784
16 4
3239
1391
3867
1656
4) Calculation of TAT
TAT can be calculated by adding the host communications time to the actual communications time.
The host communications time varies depending on the communications settings and the codes that
you specify.
Example of calculation: when operating in Single Access Mode and Trigger Mode to read 1 page (4
bytes) data
Code-specified in ASCII:
The total number of characters is 29, i.e., 15 characters in the command part and 14 characters in the
response part. From this, the host communications time would be 29 * 11 bits /38400(bps) * 1000 = 8.3 (ms).
The communications time would be14 ms for Fast Mode and 92.9 ms for Standard Mode. TAT, therefore,
would be 8.3 + 14 = 22.3 ms for Fast Mode and 8.3 + 92.9 = 101.2 ms for Standard Mode.
Code-specified in HEX: