Kramer Protocol
39
Table 18: Protocol Definitions
MSB
LSB
DESTINATION
INSTRUCTION
D
N5
N4
N3
N2
N1
N
0
6
5
4
3
2
1
0
1st byte
INPUT
I6
I5
I4
I3
I2
I1
I
0
6
5
4
3
2
1
0
2nd byte
OUTPUT
O6
O5
O4
O3
O2
O1
O
0
6
5
4
3
2
1
0
3rd byte
MACHINE NUMBER
OVR
X
M4
M3
M2
M1
M
0
6
5
4
3
2
1
0
4th byte
1
st
BYTE: Bit 7 – Defined as 0.
D – “DESTINATION”: 0 - for sending information to the switchers (from the PC);
1 - for sending to the PC (from the switcher).
N5…N0 – “INSTRUCTION”
The function that is to be performed by the switcher(s) is defined by the INSTRUCTION (6 bits). Similarly, if a function is performed
via the machine’s keyboard, then these bits are set with the INSTRUCTION NO., which was performed. The instruction codes are
defined according to the table below (INSTRUCTION NO. is the value to be set for N5…N0).
2
nd
BYTE:
Bit 7 – Defined as 1.
I6…I0 – “INPUT”.
When switching (ie. instruction codes 1 and 2), the INPUT (7 bits) is set as the input number which is to be switched. Similarly, if
switching is done via the machine’s front-panel, then these bits are set with the INPUT NUMBER which was switched. For other
operations, these bits are defined according to the table.
3
rd
BYTE:
Bit 7 – Defined as 1.
O6…O0 – “OUTPUT”.
When switching (ie. instruction codes 1 and 2), the OUTPUT (7 bits) is set as the output number which is to be switched. Similarly, if
switching is done via the machine’s front-panel, then these bits are set with the OUTPUT NUMBER which was switched. For other
operations, these bits are defined according to the table.
4
th
BYTE: Bit 7 – Defined as 1.
Bit 5 – Don’t care.
OVR – Machine number override.
M4…M0 – MACHINE NUMBER.
Used to address machines in a system via their machine numbers. When several machines are controlled from a single serial port, they
are usually configured together with each machine having an individual machine number. If the OVR bit is set, then all machine
numbers will accept (implement) the command, and the addressed machine will reply.
