user manual
VP-1608 - Kramer Protocol 2000  37 
12  Kramer Protocol 2000 
The Kramer Protocol 2-000 RS-232/RS-485 communication uses four bytes of 
information as defined below.  
MSB 
LSB 
DESTINATION   INSTRUCTION 
 0  D  N5  N4  N3  N2  N1  N0 
7  6  5  4  3  2  1  0 
1st byte 
INPUT 
1 
I6 
I5 
I4 
I3 
I2 
I1 
I0 
7 
6 
5 
4 
3 
2 
1 
0 
2nd byte 
  OUTPUT             
1 
O6 
O5 
O4 
O3 
O2 
O1 
O0 
7 
6 
5 
4 
3 
2 
1 
0 
3rd byte               
      MACHINE NUMBER       
1  OVR  X  M4  M3  M2  M1  M0 
7 
6 
5 
4 
3 
2 
1 
0 
4th byte 
1st 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). 
2nd 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. 
3rd 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. 
4th 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 accept (implement) the command, and the addressed machine replies. For a single 
machine controlled via the serial port, always set M4…M0 = 1, and make sure that the machine itself is configured as 
MACHINE NUMBER = 1. 
All the values in the table are decimal, unless otherwise stated  
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