IDL 101
COMMUNICATION
HB_IDL101_E_V222.doc
69
Gantner Instruments Test & Measurement GmbH
10.3. PROFIBUS-Protocol
10.3.1. Transmission Sequence
In the PROFIBUS-protocol data are transmitted from and to the data logger by means of the following sequence:
SD .. .. .. .. .. .. ED SD .. .. .. .. .. .. .. .. .. .. ED SD .. .. .. .. .. .. .. ED
request telegram response telegram request telegram
T
1 T 2
T
1
: time between request-telegram and corresponding response-telegram
T
2
: time between response-telegram and next request-telegram
You will find the minimum and maximum appearing values for T
1
and T
2
and the adjustment range in the following
table 10.11.
protocol baud rate T
1
T
2min
T
2max
adjustable no no yes
PROFIBUS
9.6 kbps
19.2 kbps
1.5 CT
(16 BT)
3 CT
arbitrary
Table 10.11 Values and adjustment range for the times T
1
and T
2
CT: character time: 1 CT = character length [bit] / baud rate [bps]
BT: Bit-Time: 11BT = 1CT
Notice
: In the PROFIBUS-protocol T
1max
amounts at least 2 msec with the baud rates 9.6 kbps and 19.2 kbps.
The values for T
1min
and T
2max
and the behavior of the data logger if the time T
2max
is exceeded (communication timeout,
see also chapter 6.8, error handling) can be adjusted by means of the
Configuration Software ICP100
. The default
values for the time T
1
is 1.5 CT and for the time T
2max
3 CT.
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