Something strange going on....


Thread Starter

That Doug Guy

Hi Guys,
I have a good stumper for you!
I have a PC (Compaq Presario, 533 MHz) running Powers Insight to manage our System 600 building control network.

It works ok on this new PC although the data doesn't seem to refresh as quickly as it did on the old 486 we were running a few weeks ago.

The PC connects to the LAN (System 600 network) via a RS232 on COM 1. This then is connected to a "box" which I believe is an RS232 to RS485 converter. Then out to the network.

Here's the screwy part.

If I try to use my modem which lives on COM 2 the connection to the network dies. the data does not refresh and it just dies this horrible slow death. As soon as I cut the modem connection it
bounces right back.

Here is the dope on the network connection and the modem:

Here is the MODEM:

HSP56 MicroModem by PCtel Inc. (came with the system) Hardware Version 002

Dos Support
Base Address 2F8
Interrupt 3

Windows says this modem is at IRQ 3 with and I/O Range of 14C0 - 14FF

Here is the dope on COM 1:

Serial Port

I/O Range: 03F8 - 03FF

Any clues to this problem would be great, I am trying to use PCAnywhere with this as well as checking E-Mail via modem.


Martinicky, Brian

Hi Doug,

It looks like you are using an HSP (Host Signal Processing) modem. These are cheap modems that offload the signal processing duties of the modem onto the host CPU. That's why they are so inexpensive. A significant portion of your machine's CPU bandwidth is now being devoted to low-level modem signal processing in addition to everything else it has to do.

You should consider getting a "traditional" modem if you need that bandwidth...


Brian Martinicky
Automation Intelligence, Inc.
Hi... The non-standard base address for the modem tells me that it is a PCI modem. PCI modems can not see the standard I/O address of the normal com ports as the standard com ports map to the ISA bus and not to the PCI bus that the modem sits upon. A driver performs the translation between the two. I have seen
conflicts between a serial device connected to a true serial port (your System 600 connection on Com1) and a PCI modem auto-assigned as Com2.

What you need to do is go into the machines CMOS and see if the second hardware Com port on the motherboard is disabled. I am willing to bet that the second port is disabled. This fact then allows the PCI modem to map Com 2. Enable the second hardware Com port on the motherboard. The PCI modem will then map to Com 3. At this point as long as you are running the Win98 (it shares IRQ lines properly) and Insight can work with a shared IRQ you should be ok. If not, switch the Insight connection to Com 2. Hope this helps...

Best Regards... Rick Kelly

Chief Technician
Natural Cuts
Cheese Operations
Kraft Canada
(613) 537-8069 V
(613) 537-8057 F
[email protected] Inc.

Alex Pavloff

What I think the problem is:

Your modem is what's commonly known as a Winmodem. 3Com started it, but many companies have followed suite. They basically pull most of the expensive hardware off the modem and make the operating system do all the work. Sounds to me like:

1) You have a computer that can't deal with the extra load that the modem puts on it
2) The driver for the modem for you particular OS has problems.

Try getting updated drivers -- if that doesn't work, about your only hope is to go get a real modem. External modems, while costing more, are your best bet for finding a non-software driven modems. The more expensive internal modems are usually also non software modems.

Alex Pavloff
Software Engineer
Eason Technology