Modem vs Visa

[chyrus]

Hello,

I've my labview stand alone application that talks with an external device over RS232. The things go well with every kind of modem (analog or gsm type), but when i try to use the internal one (Pctel hsp56 MR data/fax), although the same parameters settings ( no flow control hard&software beyond the same AT parameters setting, i hope! ) when i run Visa close, the modem hang up. The same thing does not occurs when i use others modems with the same code. Has someone idea of the AT command that is related to Visa close?

Thanks for your attention,

Have a good code.

Chyrus

[LuI]

Hi,

AFAIK there is no relation. Those two commands are on different layers of the protocol. AT-commands are issued using VISA.

I'd suspect some default settings made by VISA at close with some of the flow control lines. You may try to use NI-SPY to look for such. As this is an internal (and maybe even virtual) modem you may not be abel to measure the flow control line levels.
Greetings from Germany!
--
Uwe