Technical data

MESOMATIC Automation und Messtechnik GmbH D-71394 Kernen
Telegram from Profibus Master to the DK900 (command, instruction):
Byte Description
0 Control byte
Bit 7 Toggle bit, after the start of the DK900 the toggle bit is
= 0.
Bit 6 0, no meaning
Bit 5 0, no meaning
Bits 4..0 Number of characters, starting with Byte 1
1 1st character to be transmitted
2..31 Subsequent characters
Table 3 Bidirectional channel (Master ® DK900)
Important! If the SFC15 "DPWR_DAT" function is used to write data, the toggle bit (Bit 7)
must be paid special attention to when treating Byte 0. Every time the toggle bit
changes its state (both when changing from 0 ® 1 and when changing from 1 ® 0),
a transmission process is triggered.
If, for example, the current state of the toggle bit is 1, and a new number of
characters is loaded into Byte 0 by a simple loading instruction, this loading
instruction alone already causes the state of the toggle bit to change from 1 to
0, thus triggering a transmission process.
DK900 15