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• Understand data acquisition concepts

• Understand volt-free contact measurement

• Understand sensor fundamentals

• Know the common sensors used for point and track circuit monitoring

• Know how to “identify” a site

• Know how to select sensors and volt-free contacts for differing point machine arrangements

• Know how to “size” and select the most appropriate data loggers

• Know the correct earthing arrangement for Mpec data loggers

• Be able to produce of installation drawings

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title Site Identification
Every data logger that is to be connected to the Network Rail RADAR system must: Follow a defined naming convention Have a unique device ID Logger Name The naming convention is of the form Engineers Line Reference (ELR): Local Location Code specified by the local delivery unit, followed by an underscore, followed by the route name a Engineers Line Reference (ELR), followed by an underscore, followed by a 2 digit number The 2 digit number is used to identify an individual data logger if more than one data logger shares the same ELR. location. Info Contact the Network Rail Delivery Unit to obtain a list of preferred logger names Device ID Every Mpec data logger connected to the Network Rail RADAR system must be assigned a unique device ID by the Network Rail RADAR team. The number will be between 1 and 65,534. No other RADAR logger must share this number. Note Info Each Network Rail delivery unit manages a “pool” of device IDs. Contact the Network Rail Delivery Unit to obtain a list of device IDs Note If numbers are shared, the RADAR system is unable to map the incoming asset data to the correct asset in the RADAR server system.

The SA380TX is more expensive than the SA380TX-L, it does however have advanced features, such as the touchscreen, battery back-up, advanced data processing options and master/slave capability.

SA380TX-L Hardware Variants

Master / Slave Devices

As stand-alone devices, each data logger will require an active SIM and GSM antenna in order to transmit data to the RADAR system. This can become troublesome for large installations installed in tight spaces.

Using a “Master / Slave” arrangement permits up to 7 SA380TX-L devices to connected over RS485.

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All data is marshalled through the master SA380TX device. Consequently all configuration, data collection and transmission, is controlled from the master SA380TX. In theory the maximum number analogue channels become 78, and digital channels becomes 166.

The RS485 link can become overloaded when used for point monitoring if all the monitored point ends move concurrently. Mpec recommend the following limitations:

Digital Event Monitoring

Straight forward. Select the volt-free-contacts you wish to monitor and connect them.

• Check that polarity across the contact is correct.

• You may use Front or Back contacts

• You can be creative, using logic if you are short of inputs

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DC Track Circuit Monitoring

Consumes 1 x Analogue Channel per track circuit.

Straight forward. Connect 1 x Rowe Hankins 600 mA CT such that it captures the current flowing through the track relay coil.

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Point Machine Monitoring

One Motor CT - Relay Triggers

This solution consumes 1 x Analogue Channel and 2 x Digital Channels (max) per point end.

Current carrying conductors that carry full motor current in both directions of movement to pass through a PCM20 CT in the same direction. CT produces a positive direction waveform under all scenarios

• Command / Calling Relays

• Motor Relays

• Detection Relays

• Where no VFCs exist - Use “trip” output current clamps.

When monitoring multiple ends of the same point identity, VFC trigger inputs can often be shared amongst triggered captures, economising on inputs.

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Using time-of-operation Relays (Calling or motor relays that pick when the motor runs)