COM Port question - fast help needed!

[sterankin]

Hi there, my boss has just asked me a question, and I need to know the answer soon.

I was hoping someone here can help me.

I have to do a VB program, which will read in information from a set of scales via the RS232 COM?) port.

Problem is, that there are 6 - 8 scales that have to be connected at one time to the back of the PC - Is this possible via some sort of device, Can you have 6 COM ports on the back of a pc?


In VB, can you have several instances of the MSComm active x, one to communicate with each COM port?

I hope this is clear, and I hope you can give me some advice as to the feasibility of this project........

Many thanks.

[jim mcnamara]

Yes. Laboratories often have a bunch of RS232 connections going at once. You are limited by the number of slots available on the motherboard. On special machines, I've seen COM1 - COM9.

Yes - you can have multiple instances of MSComm. It's better to have a control array to reduce the lines of code.

Now -as to whether this is feasible - means can you afford the hardware, and can someone do the programming needed?
Can you get the code working 100% in a reasonable time frame?
I cannot answer the feasiblility question.

Generally for problems like this, you are MUCH better off not re-inventing the wheel. Buy software and hardware bundled and already to go. Let somebody else support it. It will cost your company less in the long run.

PS: programmers are notorious for underestimating what's involved in coding and support - and they are always dying to leanr something new. This is usually a disastrous combination. Especially in terms of cost.

[sterankin]

Many thanks for your reply.

Have you any suggestions as to software/hardware bundles that could be used in this case?

Much obliged.

[JoshT]

Add-on serials ports: http://www.siig.com/products/io/pci_io.html
Does the manufacturer of your scale provide any kind of software or support for this?

[lordsty]

Ive seen 'serial hubs' that support up to 4 RS-232 connections, or cards that support mutliple RS-232 connection (example below):

http://www.equinox.com/product/multiport_main.htm

Im not sure how the card handles IRQ requests and how hard it will be to use with you application, but it may be worth looking into.

lordsty