DVR communication

ShadowUA

Hello all,
I need some help with commucations protocol DVR Infinity NDR-X5416P.
I have a litle information about protocol.
This is message format.
<BOM><ID>:<Class>:<Code>[:Operands]:<Checksum>[EOM]

Where
Symbol Value Description
: Field delimiter
<BOM> @ Beginning of message (for command)
< Beginning of message (for reply)
<ID> 00~99 Device ID
<Class> DR Device Class (?DR? for DVR systems)
<Code> AA~zz Op-code (see below)
<Operands> Optional operands defined for each operation
<Checksum> 00~99 Checksum (sum of ASCII codes before checksum discarding overflow)
[EOM] ^J^M End of message (optional: only for convenience of users using general terminal)

I am wrote function to get checksum:

Define_Function Char[256] GetFullPacket (Char Packet[])
{
local_var volatile Char ChkSum;
local_var volatile Integer i;

ChkSum = 0;

For (i = 1; i <= Length_String(Packet); i++)

ChkSum = ChkSum + Packet;

ChkSum = ChkSum + $3A; // $3A = ASCII code of ":" sing


ChkSum = ChkSum % 100;


return "Packet, ':', Format('%02d', ChkSum)";
}

When com port online :

Send_Command Data.Device, 'SET BAUD 9600,N,8,1';
SEND_STRING DATA.DEVICE, GetFullPacket("'@00: DR:vs'");

In protocol says "Checksum -sum of ASCII codes before checksum discarding overflow".
This Function is correct?

And another question - the DVR have 1 RS 485 and 1 RS 232. I tryed them - dont work.
Where is mistake?

AMXJeff

The function looks like it should work, can you pass us the manual?

ShadowUA

Here please

ShadowUA

And part two...

And here is analog of this DVR with analog protocol.
http://www.commandsys.com.au/dealers/downloads/LIBRARY/DEVICES/DVR/Pacom/PDR4L/DVR-protocolVer1_5_SDR40.doc

ShadowUA

I found the problem.
Problem is in the cable. Need to use nullmodem cable RS232 DB9m-DB9m, rs485 - dont work.