Mode 1 - Ct Single Word Mode - Leroy-Somer digitax st User Manual

Figure 8-2 Non-cyclic data words
8.6

Mode 1 - CT Single Word mode

The CT Single Word (Mode 1) uses one cyclic channel for non-cyclic data. This non-
cyclic sub-protocol requires a specific sequence of four or six telegrams to implement
the parameter access. Each non-cyclic word or telegram is split into two bytes to
implement the sub-protocol. The high byte containing the control codes for each
telegram and the low byte containing the data for each telegram.
By default cyclic data compression is disabled, the CT Single Word non-cyclic channel
NOTE
will be 32-bits wide (i.e. uses two words, and data must be transferred on the low word).
If cyclic data compression is enabled the CT Single Word non-cyclic channel will revert
to 16-bits and only use a single word.
8.6.1 Mapping For CT Single Word non-cyclic data
To configure an SM-PROFIBUS DP-V1 for CT Single Word mode the following steps
must be performed:
1. Set Pr MM.05 to the required mode. See section 7.2 Data formats on page 24 for
more information.
2. Set Pr MM.32 to ON to reset. See section 5.9 SM-PROFIBUS DP-V1 re-initialize on
page 20.
3. Save the parameters if required (see section 5.10 Saving parameters to the
drive for more information).
When the SM-PROFIBUS DP-V1 re-initializes, it will map cyclic data IN Word 0 and
cyclic data OUT Word 0 to the CT Single Word protocol parameter (Pr 61.50). All
existing mapping parameters will be moved down by one word, (i.e. the previous
mappings set in Pr MM.10 and Pr MM.20 will now appear in Pr MM.11 and Pr MM.21).
Table 8.3 shows what happens to the mappings when the data format is changed from
four cyclic words to four cyclic words with CT Single Word non-cyclic data.
32
Pr MM.05
1 0 4
0
1
2
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Pr MM.39
(Number of Input Words )
04
Pr MM.40
(Number of Output Words )
04
No non-cyclic data
Mode 1 - Single Word
Mode 2 - PPO 4 Word
SM-PROFIBUS DP-V1 User Guide
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