migan MPB
Large Format Numeric LED Display with InterBus Interface
microSYST Systemelectronic GmbH, Am Gewerbepark 11, 92670 Windischeschenbach
+49 9681 91960-0,
+49 9681 91960-10, [email protected], www.microsyst.de
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3.6.1 Interbus Frame for controlling the Display
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Toggle byte
Data byte 1 Data byte 2 Data byte 3 Data byte 4 Data byte 5 Data byte 6
Data byte 7
Toggle byte
The interface at the large format display is driven with the first byte of
output data (toggle byte TB).
The toggle byte is saved to intermediate memory immediately after the
InterBus interface has been initialised (first of all it must be „0“), and is
then always compared with the respectively current content of the first
byte of output data. As soon as it’s value is changed, subsequent output
data are evaluated and interface data are transmitted to the large format
display if appropriate. The only evaluation criterion is a change of con-
tent
– the actual content itself is irrelevant.
The following must be observed in order to transmit a frame to the large
format display:
The frame at the large format LED display is subdivided into blocks of
7 bytes each, which are transmitted one after the other.
The InterBus interface accepts output data transmitted by the IB
master (7 bytes) as soon as the toggle byte has been changed. As
soon as transmission of the 7 bytes of frame data to the large format
display is concluded, the output data transmitted by the IB master are
mirrored to the input data at the IB master (8 bytes).
The next block cannot be transmitted until input and output data are
identical (the comparison of the toggle byte is sufficiently).
If the last block of the protocol requires less than 7 bytes, the unused
bytes must be set to 00h (they are not sent).
