|
The following illustration shows a typical screen.
Architecture
The Print Monitor
program suite consists of four Win32 executables and a custom Windows
font file.
- m16prcol.exe - the data
collector program
- m16prmns.exe - the
communications server program
- m16prmon.exe - the master
program
- m16prmnc.exe - the client
program
- iscterm.fon - the fonts
used for master and client
data displays
The component programs
perform specific functions that are described in detail in the
sidebar on this page. The programs communicate with
each other by means of named pipes. This communications
mechanism allows the user to install the Print Monitor system in a
number of different ways. Two examples are given here.
Minimal Configuration
In a minimal
configuration, only the data collector, server and master programs
need to be installed, and they can all run on the same workstation,
which does not have to be on a local area network.
Networked Configuration
In a networked
configuration, the data collector, server, master and one or more
client programs can run on different machines. A typical
installation is illustrated below.
|
Functions of the Master Client
The Master program,
m16prmon.exe, is an ordinary Win32 application. It accepts
Manager-16 printer data from the server, formats it and displays it
in a scrollable, re-sizable window. The
contents of the window can be printed to any local or networked
printer that might be installed on the host machine.
Manager-16 status and
alarm messages are displayed in the master window as red text.
Manager-16 reports and operator console screen dumps are displayed in
blue. These latter displays generally contain both text and graphic
elements. They are rendered using custom fonts, supplied with the
program suite in a separate font file. This font file should be
installed in the same directory as the master executable.
Two font sizes are
available, but they are not manually selectable. The font size used
depends on the resolution of the Windows desktop on which the master
is running. If the desktop resolution is under 1280x1024, the
smaller of the two fonts is used. If the resolution is 1280x1024 or
greater, the larger of the fonts is used.
As new messages,
reports and screen dumps are received at the master, they are added
to the bottom of a display buffer. The buffer can hold up to 1024
lines of data. The operator can use the window's vertical
scroll bar to bring any part of the display buffer contents into
view. To see the latest information available, the user should
scroll to the bottom of the buffer.
The master program has
a menu system that allows the user to specify the name of the
computer running the server and to then connect to the server and
start receiving data. Printing of the data window is also controlled
with the menu system.
The Master program also
has menu facilities allowing the user to control the operation of the
data collector. Using the Master program's menu system, the
user can set the following parameters:
- log file pathname
- logging on/off
- archive file pathname
- archiving on/off
- archive time
- serial port
- serial communications
on/off
- serial baud rate
In a minimal
configuration, the master program can run on the same machine that
runs the data collector and the server. In a networked
configuration, the master can run on any host machine that has access
to the machine running the server.
Functions of the Aux Client
The client program,
m16prmnc.exe, provides a subset of the functions of the master
program. Like the master, it accepts Manager 16 printer data from
the server, formats it and displays it in a re-sizable,
scrollable window. It also supports printing of the contents of the
window. Unlike the master, it does not support control of the data
collector.
Running one or more
clients is optional. The number of clients supported by the Print
Monitor system is dependent on the type of license the user has. In
a minimal configuration, the master, data collector and server are
all installed on one machine, and no client is used. In a networked
configuration, multiple clients can be run on separate networked
hosts, provided they all have access to the machine that is running
the server. However, it is not possible to run multiple instances of
the client on the same host.
System Requirements
Minimum configuration: One PC running Windows NT4.0,
2000 or
XP, CPU and memory appropriate to operating system, one available
serial port.
Networked configuration: Each PC running Windows NT4.0,
2000
or XP, cpu and memory appropriate to operating system, Ethernet. The PC
running the
collector program must have one available serial port.
|
Functions of the Data Collector
The data collector,
m16prcol.exe, runs on a PC that is connected by an RS-232 serial
cable to the Manager-16 processor's printer port. The data
collector is a Win32 service. It has no user interface (no Window)
of its own. It is intended to run all the time as a background task.
While it typically runs under the authority of an ordinary user, it
is installed and set up to start and run automatically, so that the
user does not have to log on and manually launch it. Once installed
and started, it's operation can be controlled from the Print
Monitor Master program.
The data collector
program receives the serial data output from Manager-16 processor's
system printer port and routes it to the server program, which
distributes the data in turn to the master and optionally to one or
more clients. The data collector also handles logging of the
incoming data to a file, and automatic backup of the log file. When
logging is enabled, the data collector examines the stream of
incoming data to determine what parts of the stream constitute status
and alarm messages. It extracts and formats these parts and writes
them to a user-designated log file, which is typically a file on the
local host. When backup is enabled, the data collector periodically
(once a day, at a user-designated time), backs up the log file to an
archive file, which is typically on a remote host. If the backup
file on a remote host and temporarily unreachable, the data collector
will retry the backup automatically every 30 minutes until the backup
succeeds.
Note that logging is
performed only on status and alarm messages received from the
Manager-16 processor. Status and alarm messages constitute only one
of three different types of output available from the Processor.
Besides status and alarm messages, which are simple text messages,
the processor can output reports of various kinds. It can also
output representations of the Manager-16 operator console screens.
Reports and screen dumps generally make use of special graphical
characters; therefore they do not lend themselves to logging in the
same way that status and alarm messages do. Reports and screen dumps
are simply passed on to the master and client programs, which can
represent them in their windows and print them on hard-copy devices.
Serial communications
parameters, log file parameters, and backup parameters can be set by
the user of the master program. The master program translates the
user's settings into data collector commands and sends these
commands to the data collector by way of the server. The data
collector responds to commands from the master with status
information that is routed back to the master by way of the
server.
Functions of the Server
The server,
m16prmns.exe, is also a Win32 service application with no user
interface of its own, intended to run constantly “in the
background”. It function is to establish and control the
communications channels that are used by the other Print Monitor
component programs. Communications between the component programs
are handled by named pipes. This mechanism supports communications
equally well whether the communicating programs are running on the
same host or on different hosts connected by a network.
The server function is
implemented in a separate executable in order to facilitate security
measures that are necessary when communications takes place over a
network. In a minimal configuration of the Print Monitor system, the
data collector, server and master all run on the same PC under the
same user's authority. In a networked configuration, the
server is typically run on a designated server machine under the
authority of the system administrator. The system administrator can
control which users can connect to the server's pipes over the
network by creating a Print Monitor user's group and making
those users members of the group. When the administrator installs
the server, he or she specifies to the server the name of the group
he has created, whose members will have access to the pipes the
server manages.
The server creates and
controls four bi-directional pipes. One pipe is used to receive data
from the collector program, another is used to transmit this data to
the master and client programs for display, and to receive status
information from the master and clients. A third pipe is used to
receive commands from and transmit status information to the master.
The fourth pipe is used to transmit commands to and receive status
information from the data collector.
|
