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The T/Mon LNX ASCII Processor

By Morgana Siggins

November 4, 2020


Diferrent from other communication protocols that may be used to report alarm information, ASCII is free-form, non-standard, and may say almost anything.

So, if you have remote ASCII-enabled devices that you need to keep an eye on, you need a powerful monitoring master station. Your master should be able to monitor the English output of your telecom network and declare alarms based on your selection criteria from ASCII devices like switches, PBXs, and routers.

That's where the T/Mon LNX comes in. T/Mon's ASCII processing is a powerful and flexible feature that allows you to have complete visibility over your ASCII devices at all times.

If you have an ASCII network and are planning to deploy the T/Mon, or need to know if T/Mon is a good option for you, read on. We'll dive into how you can set up the T/Mon ASCII processor for the first time.

What is ASCII?

American Standard Code for Information Interchange (ASCII) is a code for representing 128 English characters as numbers, with each letter assigned a number from 0 to 127. In other words, ASCII is character table that translates letters to hex representations. For example, the ASCII code for uppercase M is 77.

ASCII is pronounced "as-kee".

The majority of computers use ASCII codes to represent text. This makes it possible to transfer data from one computer to another.

Text files stored in ASCII format are usually called ASCII files. Text editors and word processors are usually capable of storing information in ASCII format, although ASCII format is not always the default storage format.

From a monitoring point of view, ASCII is any human-readable text message that you might see on a printer or command console.

ASCII appears in a huge range of devices, but it almost always look different. Nonetheless, humans can always read and understand ASCII reports.

ASCII differs from traditional protocols due to its much more free form and because it's not limited to a predefined set of codes or packets. Arguably, excluding SNMP, ASCII is one of the most universal protocols.

The DPS Application

The "Printable" subset of characters

  • Letters: A-Z
  • Numbers: 0-9
  • Punctuation marks: !#?*

What Devices Does ASCII Come From?

The main devices from which ASCII comes from are:

  • Switches - 5ESS, DMS series, Siemens, etc.
  • SONET devices - OC3 and up
  • Use TL1, a very structured form of ASCII. TL1 is a "no brainer" for T/Mon to parse
  • DLS Service Provider - Calix C7
  • Digital cross connect - Tellabs 5500
  • Literally every device with a craft port

What Communications Interfaces Can ASCII Be Read From?

ASCII can be transported via:

  • Direct serial port
  • LAN (usually via Telnet session)

Sample ASCII messages from the T/Mon user manual:


What Are The Advantages of Monitoring ASCII with a Computer?

Because it's human-readable, you can theoretically have your technicians manually monitoring ASCII alarms. This is not a very efficient method, though. Using computers to monitor ASCII is a better solution. This is because computers:

After collecting ASCII alarms, computers like T/Mon LNX allow users to apply its core features to those alarms. These include qualification, history logging, alarm viewing, and automatic notifications.

T/Mon ASCII Processing

The purpose of T/Mon ASCII is to convert the ASCII source to a standard T/Mon alarm. This means that each T/Mon alarm point is databased with a regular expression rule. A specific rule will generate the alarm and another will clear the alarm.

Here's how T/Mon ASCII processing occurs:

  1. T/Mon receives a message
  2. Incoming text is sent to the ASCII processor
  3. The ASCII processor uses regular expression rules to match against a point on T/Mon
  4. When a match is found, the corresponding alarm point is modified (set or cleared)
  5. If no match is found, then the message is marked as "unmatched"

Configuring T/Mon LNX ASCII Processor

In order to configure the ASCII Processor, you first need to create a new ASCII device module. This is how you can do this:

  • Clone existing ASCII device
  • Create an instance of the device and add the IP
  • View ASCII Message Log
  • Edit Module Blueprint to add Alarm Events
  • Add regular-expression rules to trigger alarms
    T/Mon ASCII
  • Look for an existing ASCII device, and right-click on the device. Select "Clone Module" and enter a manufacturer and model.
  • Add a new instance of your device and enter in a device name.

View Message Queue

  • Select "Edit Selected Device(s)" if you haven't already
  • Click the "Syslog Queue" tab (or view "ascii" system log)
  • You will see a log of the messages that came in. This will help you create your Regex rules.

Editing the default point definitions

  • Right-click on the new device and select "Edit Module Blueprint". This will bring up a new tab that will allow editing of the device default point definitions.
  • Modify the section "default_points" to determine how new devices will be built.

Entering regular expressions

  • Create a new ASCII device and click on the "Edit Selected Device(s)" button or right click on the device and select "Edit".
  • Click on the "ASCII Rule" tab and click on the "Add" button.

Editing the ASCII processor script

  • Right-click on the ASCII device and select "Edit Module ASCII Processor"
  • If using a predefined set of alarms points leave the process section so it looks like the following:
    T/Mon ASCII
  • If utilizing AutoASCII, leave the "default_points" empty in the device Blueprint file and adjust the process function so it looks like the following:
    T/Mon ASCII
  • Create a routine called autoDbRules that returns an array with 3 items; "auto", "clr", and "desc".
    • "auto" is the regular expression used to generate the alarm.
    • "clr" is the regular expression used to generate the clear.
    • "desc" is the regular expression used to build the point description
  • The ASCII processor will search through databased regular expressions first. If a match is not found, the autoDbRules array will be used to determine how to build a new point.

Sample SysLog messages:

<171>67081: Aug 8 22:25:37.875 PDT: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/20, changed state to up

<171>67082: Aug 8 22:25:39.915 PDT: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/20, changed state to down

Regular expressions for the previous messages are:


LINK-3-UPDOWN: Interface GigabitEthernet1\/0\/20, changed state to down


LINK-3-UPDOWN: Interface GigabitEthernet1\/0\/20, changed state to up


Auto ASCII is a good option for messages that are consistently formatted in the same way and have Alarm/Clear states. Here's the step-by-step that will help you configure that:

  • Open the AsciiProcessor.php file and create the autoDbRules() function if it does not already exist.
  • In this function, we return an array of Auto ASCII rules. Each rule has 3 parts:
    1. Auto: This is regular expression that will trigger the alarm
    2. Clear: This is the regular expression that will clear the alarm, with \1 replacing the first capture group.
    3. Desc: This is the description that gets applied to the newly created point, with \1 replacing the first capture group.

The Bottom Line

The T/Mon LNX is an integrated, multiprotocol master station that can poll ASCII and non-ASCII devices, allowing you to consolidate all your alarm monitoring on a single platform. This way you can eliminate the need for specialized terminals and reduce the number of screens your staff needs to monitor to only one.

All of your alarm data is integrated into a single display that can show you - at a simple glance - the condition of your entire network.

To know more about how T/Mon can offer significant benefits or if you have special requirements that need a custom solution, simply send us a message here.

Do you already have the T/Mon and have some questions for our tech support? Reach out to us here.

Morgana Siggins

Morgana Siggins

Morgana Siggins is a marketing writer, content creator, and documentation specialist at DPS Telecom. She has created over 200 blog articles and videos sharing her years of experience in the remote monitoring industry.