BCU 580 · Edition 11.15
39
“Inputs/outputs” module – slot 1
The digital input and output signals from the burner control
units BCU 560, BCU 565 and BCU 580 are included in this
module.
Input bytes (device
➔
controller)
The input bytes describe the digital signals which are trans-
ferred from the BCU (IO device) to the digital inputs of the PLC
(IO controller). The digital signals take up 2 bytes (16 bits).
Bit Byte n
Byte n+1
Byte n+2
For-
mat
0
Burner 1 oper-
ating signal
Max. capacity
reached1)
menox ON
BOOL
1
Burner 2 oper-
ating signal
Min. capacity
reached
1)
Free
BOOL
2
BCU system
fault
Air ON
Free
BOOL
3
Fault lock-out Pre-purge ON Free
BOOL
4
Safety shut-
down
DI ON
Free
BOOL
5
Warning
Ready for op-
eration
Free
BOOL
6
ON
Burner 2 flame
signal
Free
BOOL
7
Manual mode Burner 1 flame
signal
Free
BOOL
1)
Only with three-point step control via bus.
Output byte (controller
➔
device)
The output byte describes the digital signals which are output
by the PLC (IO controller) to the BCU (IO device). The digital sig-
nals to control the burner control unit BCU occupy 1 byte (8 bits).
Parallel to the bus communication, terminals 1 to 4, 44 and
50 of the BCU can be wired. This allows the BCU to be con-
trolled using the digital signals of the bus communication or
the inputs at the terminals.
In the event that the bus communication is faulty or interrupted
and during the initialization of the bus communication after
switching on, the digital signals are interpreted as “0”. If the
BCU is controlled using the inputs at the terminals during this
time, the normal program runs even if the bus communication
is faulty or interrupted.
Bit Byte n
Format
0 Reset
1)
BOOL
1 Burner 1 start
1)
BOOL
2 External air ON
1)
BOOL
3 Pre-purge ON
BOOL
4 Burner 2 start
1)
BOOL
5 menox ON
BOOL
6 Open control element, three-point step Open
2)
BOOL
7 Close control element, three-point step Close
2)
BOOL
1)
Parallel to the bus communication, terminals 1 to 4 can be
wired.
2)
Only with three-point step control via bus.
Profinet > GSD file for PLC configuration > Modules for cyclic data exchange
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