VEGA VEGACOM 557 Profibus DP - Manual (Page 43)

VEGACOM 557 Profibus DP 43
Data image in VEGACOM 557
Image of the contact outputs on LOGBUS in mode 6E6A
Beside the previously described individual PC/DCS values, also the switching status of the
VEGA processing system VEGALOG 571 can be transmitted via VEGACOM 557.
These are:
- status of the contact outputs of the AR cards (relay contacts)
- status of the contact outputs of the A T cards (transistor outputs)
Control command 0xCE (LOGBUS)
In contrast to the image of measured values, the image of switching status is „Bit orientated“.
In VEGACOM 557 a switching status is represented by one Bit, whereby all available informa-
tion of a VEGALOG 571 output car d (AR or A T) is saved in one data wor d of 16 Bits (= 2 Byte).
A data wor d of 16 bit exists for each output (AR / A T) on the LOGBUS (module 1...32), i.e.
max. 32 data words at 16 bit each.
A VEGALOG ouput car d (AR/AT) has max. 10 output contacts (RK), which ar e bit coded in
one data word (2 Byte). If the respective Bit is 1, the output contact is closed, if the respective
Bit is 0, the output contact is open. The most significant bit of the data word contains the status
information. If the status bit is 0, the output information is valid, if the status bit is 1, the output
information is invalid.
With control command 0xCE, the switching status of two VEGALOG output cards can be read
out per enquir y.
The enquiry telegram, written by the Profibus-Master into the 6 Byte outputs, is structured as
follows:
Byte1 Byte2 Byte3 Byte4 Byte5 Byte6
control
command
reserved
module
number
reserved reserved reserved
0xCE 1...32 0xFF 0xFF 0xFF 0xFF
6 Byte
Format of the enquiry acc. to contact outputs (LOGBUS)
VEGACOM 557 writes the answering telegram shown on the next page into the 6 Byte inputs
of the Pr ofibus-Master.