7-1 Turn Around Time and Communication Time
7-1
7-5
（
2
）
Communication time in
Multiple modes:
The communication time when the commands with multiple access options
are used varies depending on operating conditions. Those conditions
include the number of bytes, as well as the number of Tags in the
communication area. The mean values in consideration of these conditions
are shown in the table below.
：
The transmission rate of the Tag is set in Fast Mode as factory default.
7-1-3 Turn Around Time (TAT) Calculation Method
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:
The total number of characters is 33, i.e., 15 characters in the command
part and 18 characters in the response part. From this, the host
communications time would be 33 * 11 bits /38400(bps) * 1000 = 9.5 (ms).
The communications time would be14 ms for Fast Mode and 92.9 ms for
Standard Mode. TAT, therefore, would be 9.4 + 14 = 23.5 ms for Fast Mode
and 9.4 + 92.9 = 102.4 ms for Standard Mode.
：
・
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.
Example of Multiple Access communication
time: I.CODE SLI Chip
（
msec
）
2 pages (8 bytes) to read (ms)
2 pages (8 bytes) to write (ms)
Number of
Tags
Fast mode
Standard Mode
Fast mode
Standard Mode
2 115 749
161
1103
4 192 1300
285
2009
8 338 2354
525
3773
16 639 4511
1013 7349
