Lucent Technologies PassageWay Service Provider For PARTNER Communications System Getting Started

							Troubleshooting
4-22
Failure Code -121
Meaning: The PC and the PassageWay adapter cannot communicate
over your serial port.
Things to Try: Follow the instructions for Failure Code 111.
Failure Code -131, -132, -133, or -135
Meaning: The PC cannot communicate properly with your PassageWay
adapter.
Things to Try: Try replacing any RS-232 cables or adapters you are using
between your PC’s COM port and the PassageWay adapter’s 25-pin
connector.
Failure Code -134 or -141
Meaning: The PassageWay adapter cannot communicate properly with
your telephone.
Things to Try: Try replacing the 7-foot telephone cable between the
PassageWay adapter and your telephone.
Failure Code -200 and above
Meaning: A conflict or application error has occurred which prevented
Connect from operating your PC serial port.
Things to Try: Try closing all Windows applications except Connect and
Windows Program Manager (for Windows 3.1 or later), and then try the
test again.
You may need to modify your AUTOEXEC.BAT and CONFIG.SYS files to
eliminate this conflict. 
						

							Troubleshooting
4-23
Problem 3: Connect will not work on COM ports other than COM1 and
COM2.
By default, many PCs are not configured to permit the simultaneous use of
three or more COM ports. Specifically, most PCs are configured such that
COM ports are grouped into pairs: COM1 is paired with COM3, and COM2 is
paired with COM4. By default, such PCs permit only one COM port from each
pair to be operating at the same time (for example, COM1 with COM2). COM
ports within the same pair will usually conflict with one another and are not
supported (that is, COM1 with COM3, or COM2 with COM4).
If you cannot get Connect to work properly on COM3, check if another device
is using COM1 at the same time. Similarly, if you cannot get Connect to work
on COM4, determine if another device is using COM2 at the same time. If so,
you may need to make some changes to your PC configuration to support
using the PassageWay Service Provider on COM3 or COM4. Refer to
Appendix A for more information. If you need additional assistance in setting
up devices on COM ports other than COM1 and COM2, consult your PC
hardware vendor.
Problem 4: Connect occasionally displays its initialization window while
one or more PassageWay applications are running.
Connect displays its initialization window whenever it establishes (or re-
establishes) communication with the telephone. Generally, this window is
displayed only once, at the time when a single PassageWay application is first
executed. However, if a communications problem occurs at any time,
Connect attempts to clear the problem by reinitializing itself, which causes the
initialization window to reappear temporarily. If this occurs while a
PassageWay application is performing a task involving the telephone, the
operation in progress will be aborted and must be restarted manually once
the initialization window disappears. If no task involving the telephone is in
progress during this process, the operation of PassageWay applications is
unaffected. 
						

							Troubleshooting
4-24
The chance of a communications problem depends on your PCs
configuration. The PassageWay Service Provider operates at a data rate of
4800 baud, and it relies on Windows to manage the flow of data through your
PCs serial port. Depending upon the speed of your PC, the number and type
of applications you are using, and various hardware components in your PC
configuration, Windows will be able to manage serial communications with
varying degrees of effectiveness.
If you encounter frequent communications errors using the PassageWay
Service Provider, your PCs current hardware configuration may not support
reliable high-speed communications under Windows. Appendix A includes
information about choosing serial port hardware that can work reliably at high
speeds under Windows.
Problem 5: Connect will not run. It displays the message: 
Connect must
terminate due to an unexpected communications error and
then terminates.
This message indicates that Connect cannot communicate with the COM port
you specified using the PassageWay Configurator. Run the PassageWay
Configurator and select a different COM port. 
						

							PC Serial Ports
A
A-1
Overview
This appendix provides detailed information about PC serial ports, including
background information about what they are and how they work.  It also
explains how Microsoft Windows 3.1 manages serial ports, how to resolve
problems using COM3 or COM4 under Windows, and how to choose serial
port hardware that is well-suited to the PassageWay Service Provider.  If you
are familiar with serial port terminology (for example, I/O port addresses,
IRQs, etc.), you may wish to skip over the background section.  If not, you
should review the background section before reading further.
If you are having problems using the PassageWay Service Provider on COM3
or COM4, you should refer to “Workarounds and Solutions to the IRQ Conflict
Problem.”  If you intend to purchase an add-on serial port card for use with
the PassageWay Service Provider, you should refer to “Selecting an Add-On
Serial Port Card” for information that can assist you in selecting a card. 
						

							PC Serial Ports
A-2
Background
Serial ports (also sometimes referred to as communications ports or COM
ports) are hardware interfaces that permit your PCs microprocessor to
communicate with peripheral devices using a communications standard
called RS-232 (hence, serial ports are also sometimes referred to as RS-232
ports).  Many common computer accessories make use of serial ports,
including serial mice, modems, and serial printers.
Under DOS (and Windows, which works cooperatively with DOS), the serial
port interfaces in a PC are uniquely identified by specific device names:
COM1 (“serial communications port 1”), COM2 (“serial communications port
2”), and so on, usually up through COM4.  A particular PC might have none of
these devices, some of them, or all of them installed.  For example, most PCs
currently on the market arrive from the manufacturer with two serial ports
already installed (COM1 and COM2), often integrated onto the computers
main system board.  Installing additional serial ports (for example, COM3 or
COM4) is usually accomplished by purchasing an add-on card and installing
it into a free expansion slot.
For most purposes (such as configuring software), the generic description of
serial ports provided by their device names is sufficient.  For example, during
the PassageWay Service Provider installation procedure, you are asked to
provide the device name of the serial port to which you have connected the
telephone (for example, COM2).  Unfortunately, this abstract view of serial
ports is not sufficient for other purposes, notably for troubleshooting
problems:  To be able to do this effectively, a basic understanding of serial
port hardware is required.  In particular, it is essential to understand the
mechanics by which the computers microprocessor communicates with serial
port hardware. 
						

							PC Serial Ports
A-3
The microprocessor/serial port communication consists of two aspects:  an
I/O port address and an interrupt request signal (IRQ).  The I/O port address
represents a small region of the microprocessors input/output memory space
that is used to pass data back and forth to the serial port.  This memory
region acts something like a mailbox:  Outgoing mail (data from the
microprocessor to be transmitted to the peripheral device) is placed in the
mailbox by the owner (the microprocessor) to be picked up by the mail carrier
(the serial port hardware) for subsequent delivery to the destination party (the
peripheral device).  In turn, the mail carrier (the serial port hardware) places
incoming mail (data from the peripheral device) into the box to be picked up
by the owner (the microprocessor).  This analogy illustrates an additional
important point about I/O port addresses:  Just as individual mailboxes help
the residents in a neighborhood keep their mail from getting mixed up, each
device using an I/O port address to communicate with the microprocessor
should have a unique address that does not conflict with that of any other
device.
IRQ Mechanism
The mailbox analogy is also helpful in understanding the IRQ mechanism.
Normally, we place our outgoing mail in our mailbox at any convenient time
before the mail carrier arrives to pick it up.  The outgoing mail sits in our
mailbox until the mail carrier arrives, at which time it is picked up and possibly
some incoming mail is placed in the mailbox.  Then, some time later, we
check our mailbox and retrieve our new incoming mail.  The problem with this
scheme is that it is not very efficient;  both the outgoing and incoming mail
spend some time just sitting in the mailbox.  A better approach would be if
the mail carrier provided some sort of signal (for example, ringing the
doorbell) to announce his or her arrival, in which case we could hand over the
outgoing mail and pick up the incoming mail immediately. 
						

							PC Serial Ports
A-4
In the PC architecture, IRQs acts like the doorbell in our analogy:  They
provide a method by which hardware devices in the computer can get the
microprocessors attention to deal efficiently with some process.  The serial
port hardware makes use of an IRQ to announce that it is ready to receive
more outgoing data and/or that new data have arrived from the peripheral
device that need to be processed.
Like I/O port addresses, IRQs must generally be unique among the active
hardware devices in a computer system.  In the mailbox analogy, the doorbell
is probably not a good signal since virtually anyone could ring the doorbell for
any number of reasons, not just to indicate the arrival of mail.  Similarly, if a
particular IRQ signal is used (PCs generally support 16 unique IRQ signals,
denoted IRQ0, IRQ1, and so on, up through IRQ15), the microprocessor must
take the appropriate action for the device associated with that IRQ.   If there
is a mix-up, or if more than one device attempts to use the same IRQ at the
same time, a conflict occurs, and the outcome is often unpredictable and
usually undesirable (for example, the computer may “hang”).  Because IRQs
are a limited resource, some newer PCs support IRQ sharing, a hardware
mechanism that permits more than one device to make use of the same IRQ,
but most PCs do not.  For example, all PCs that use IBMs MicroChannel
Architecture (MCA) support IRQ sharing, as do most PCs that use the
Enhanced Industry Standard Architecture (EISA) design.  However, most PCs
in the marketplace -- even new models -- are based on the traditional Industry
Standard Architecture (ISA), which generally does not support IRQ sharing.
  NOTE:
IRQ sharing is a PC feature. If your PC supports IRQ sharing, you can
put two COM ports on one IRQ. You will not encounter the types of
complications that this appendix addresses if your PC supports IRQ
sharing.
The specific I/O port address and IRQ that a particular serial port uses is
determined by the hardware configuration of the serial port.   Generally, these
parameters cannot be changed for built-in serial ports, but add-on cards
containing serial ports often provide jumpers or switches that can be used to
configure them to use one of several I/O port addresses and IRQ
combinations. 
						

							PC Serial Ports
A-5
The table below lists the default I/O port addresses and IRQs used by the
serial ports of IBM-PC/AT-compatible computers:
Serial Port
Device NameI/O Port Address IRQ
COM1 03F8 4
COM2 02F8 3
COM3 03E8 4
COM4 02E8 3
The values in this table play an important part in understanding the “wrinkles”
associated with serial ports:  although there is provision for up to four serial
ports, with four unique I/O addresses, there are only two unique IRQs
associated with them (recall that most PCs require the IRQs used by each
active device to be unique to avoid conflicts).  To understand why, it is useful
to recall what the PC world was like before the widespread availability of
products like Windows.
When the architecture of the current generation of PCs was first being
designed (for the IBM PC/AT), the concept of multitasking was not nearly as
important in the PC marketplace as it is today.  Consequently, since DOS
(before Windows) did not permit multiple applications to run simultaneously
(with the notable exception of certain specialized programs such as mouse
drivers), there was little need to provide a mechanism by which several serial
ports could be operated simultaneously.  Consequently, the strategy used
was to conserve IRQs by assigning the same IRQ to more than one COM port
(that is, the COM1 and COM3 ports were both assigned to IRQ4, and the
COM2 and COM4 ports were both assigned to IRQ3).  Then, under the
assumption that at most two serial ports would be active simultaneously (for
example, COM1 and COM2, which have unique IRQs), conflicts would not
occur. 
						

							PC Serial Ports
A-6 Serial Ports Under Windows 3.1
Unlike the DOS-only world of yesterday, todays multitasking environments
like Windows permit the microprocessor to communicate with up to four active
serial port devices at the same time (COM1 through COM4).  For example,
under Windows, if you are using a serial mouse (on COM1) within a terminal
emulator program that operates a data modem (on COM2), while using a fax
board (on COM3) to transmit or receive a fax “in the background,” you are
using three serial port devices simultaneously.  You might even wish to make
a phone call using the PassageWay Service Provider (on COM4) at the same
time, bringing the total up to four simultaneously active serial port devices.
The fact that Windows permits this kind of powerful multitasking does not
guarantee that the underlying PC hardware can support this level of
operation, at least without some customizing at the hardware level.  Since
some PCs can support it by default (for example, those that support IRQ
sharing), Windows does not prohibit you from configuring your system and
attempting tasks like the one in the previous paragraph.  Unfortunately, most
PCs cannot support this operation by default, and the most likely result of
attempting the above scenario is “hanging” the PC due to an IRQ conflict.  On
such systems, using COM1 along with COM2 is generally fine (recall that
these devices have unique IRQs by default), but the addition of COM3 or
COM4 causes the system to fail.
Fortunately, Windows 3.1 permits complete customization of all parameters
involving serial ports through the Control Panel, including configuring
nonstandard I/O port addresses and IRQs (that is, values different from those
in the table -- these parameters can be viewed and/or modified by selecting
the desired port in the Control Panels Ports icon, selecting the Settings...
button, and then selecting the Advanced... button).  This flexibility offers the
opportunity of salvation for owners of PCs that do not support IRQ sharing
who require the use of three or more COM ports simultaneously. 
						

							PC Serial Ports
A-7
Workarounds and Solutions to the
IRQ Conflict Problem
It is important to remember that the IRQ conflict is a problem in hardware; it
cannot be resolved in software alone.  Consequently, there are only three
alternatives for working around or resolving it:
Workaround 1:  Configure your serial devices such that you use only
two at any one time, and those two use serial ports with unique IRQs.
This is the simplest workaround to the IRQ conflict problem, but it does not
solve the underlying conflict.  The idea is to assign your peripheral devices to
your available serial ports in such a way as to avoid using any devices
simultaneously which might conflict.  For example, if you have a serial mouse
on COM1 (IRQ4), a fax/modem card on COM2 (IRQ3), and your telephone on
COM3 (IRQ4), you cannot effectively use the PassageWay Service Provider
since you need to use your mouse under Windows while TAPI applications are
running.
A better arrangement would be to move the PassageWay Service Provider to
COM4 (IRQ3), which then could be safely used with your mouse on COM1
(IRQ4).  In this case, the workaround is to avoid trying to use the PassageWay
Service Provider at the same time you use the fax/modem on COM2, since
the conflict now would be over IRQ3 (COM2 and COM4).
Workaround 2:  Replace one or more of your serial peripherals with
equivalent devices that do not require a serial port.
The idea with this approach is to eliminate the conflict by reducing the
number of peripherals in your system that require serial ports.  For example,
replacing a serial mouse with a bus mouse (that is, a mouse that requires its
own add-on card) would make another serial port available that then could be
used by another device.