Hi, All Expert!
I need to develop a project using VB.NET which is using RS232 communicate with Marking System. The purpose is to sent a data/text to Makring System to punch out a text.
Anybody have experince doing this type if project?
Now I have found the tools to open the serial COM port.
I have a problem to understand this Marking System Protocol, it is using the "Extended Protocol" which is provides 2 way communication WITH error checking. Using Extended Protocol we can have 'Message Format", Response Format, Message Types, and the Block Check Code (BCC) Calculations.
Message from the host computer to the marker are transmitted in the following format:
SOH TYPE [##] STX [DATA] ETX [BCC] CR
The marker may respond to the host computer in one of two way
1. If the host transmission is error free, the market response with an ackowledge (ACK) message in the form:
SOH TYPE [##] ACK STX [DATA_TEXT] ETX BCC CR
2. If am error is encountered, the marker responds with a negative-acknowledge(NAK) message in the form:
SOH TYPE [##] NAK STX [DATA_TEXT] ETX BCC CR
SOH = ASCII start of header character(001H)
Frankly speaking I dont have idea how to I use these protocol to sent a data from host/PC to Marking System vis RS232, I only manage open a COM port and sent some test, like above SOH TYPE....i got no idea how to write it.
How I can use "SOH TYPE [##] NAK STX [DATA_TEXT] ETX BCC CR" in my VB.net programming?
I can't found any books to explain for me and also can't find any example/sample from website.
I hope that those have experience in this kind of project please help me or give some tips, or can tell me where can I find information?
I am sorry if this topic is not related, but I trying to ask, hope can solve my problems.