Kramer Electronics VP-790 - Manual (Page 10)

6 VP-790 Protocol - Communication
16 = 0x10 bytes. The logical header (line 1) indicates a payload of 16 bytes
application header plus 16 bytes of the data package, i.e. 32 = 0x20 bytes.
The API answer has a payload of 0x01 byte, the error code. The data package (line
3) is 12 bytes long plus the length of the data. Therefore, the application header
(line 2) indicates now a payload of 13 = 0x0D bytes. The logical header (line 1)
indicates a payload of 16 bytes application header plus 13 bytes of the data
package, i.e. 29 = 0x1D bytes.
Direction RS232 data
PC sends command 53 41 50 01 FF FF FF FF 00 00 00 20 00 00 00 00
54 50 01 00 00 00 00 00 00 00 00 10 00 00 00 00
50 46 00 7C 00 00 00 00 00 00 00 04 92 1A 18 50
Board acknowledges to have
received a command
73 61 50 01 FF FF FF FF 00 00 00 00 00 00 00 00
Board sends answer (return
values)
53 41 50 01 FF FF FF FF 00 00 00 1D 00 00 00 00
74 50 01 00 00 00 00 00 00 00 00 0D 00 00 00 00
70 46 00 7C 00 00 00 00 00 00 00 01 00
PC acknowledges to have
received an answer
73 61 50 01 FF FF FF FF 00 00 00 00 00 00 00 00
Direction TCP/IP data
PC sends command 54 50 01 00 00 00 00 00 00 00 00 10 00 00 00 00
50 46 00 7C 00 00 00 00 00 00 00 04 92 1A 18 50
Board acknowledges to have
received a command
None
Board sends answer (return
values)
74 50 01 00 00 00 00 00 00 00 00 0D 00 00 00 00
70 46 00 7C 00 00 00 00 00 00 00 01 00
PC acknowledges to have
received an answer
None
1.7.2 Save Contrast Setting
The API byOSDContrastSave is used to store the current contrast setting in non-
volatile memory.
The API Index is decimal 125, i.e. hexadecimal 0x00 7D . There is no parameter
passed to the API function.
The return value(s) of this API function is only an error code of BYTE type, i.e. a 1
byte long. It is
0x00 if the call was successful or an error occurred if it is not zero.
Let us assume the call was successful for this example.