A Compac dispenser uses a current loop for communication. This section shows how to install the HyDip current loop adaptor (CLA) with the HyDip Fuel Tracking device to allow the remote management of a Compac fuel dispenser.

📘

HyDip does not control the measurement of fuel dispensed

This is the job of the dispenser. HyDip Fuel Tracking merely authorises each transaction, and records the measurement as made at the dispenser.

Wiring

Connect the HyDip current loop adaptor between the RS485 serial port of the HFT and connect to the dispenser (see schematic diagram below).

The current loop adapter is fitted with a short tail to attach to the HyDip device CIF port as shown here:

You will see that the current loop adaptor also has two green double-sockets, each able to take a two-wire twisted-pair shielded cable. Use these sockets to connect a cable to the Compac dispenser, with the cable shield connected to a ground point at the Compac end.

If there is good communication via the current loop between the HFT and the dispenser when the device is powered up, there should be regular flashing of the red and green LEDs on the adapter (see image below):

• a flashing green LED means the HFT is sending a command to dispenser
• a flashing red LED means the dispenser is responding

Irregular flashing usually indicates a problem with either communication, the HFT device settings or the dispenser configuration.

Attaching multiple Compac dispensers/pumps

One HyDip Fuel Tracking device with a current loop adaptor can control up to sixteen hoses:

• Up to 16 single Compac dispensing units
• Up to 8 dual Compac dispensing units
• Up to 4 quad Compac dispensing units
• Any combination of these unit types, for example 1 x quadruple, plus 2 x dual, plus 5 x single making 13 dispensers.

Each dispensing unit should be connected to the current loop adapter as shown above.

For a correctly functioning multiple dispenser system, each Compac dispenser must be identified with a unique pump number assigned to it; the Compac installation manual provides the instructions on how to assign a pump number to a dispenser.

📘

COMPAC pump numbering is not aligned with HyDip hose numbering

HFT hose numbers run from 0 - 15, while Compac pump numbers run from Pn01 to Pn16.

This means that:

• Hose 0 on HFT corresponds to Pump 1 on Compac
• Hose 1 on HFT corresponds to Pump 2 on Compac…
• …and Hose 15 on HFT corresponds to Pump 16 on Compac.

Example configuration

The table below shows how the pump numbers (Pn) and C-configuration codes would be set for the example single + double + single dispenser arrangement shown at the start of this section:

Once assigned, the corresponding hoses in the 1-2-1 example should be enabled in the HyDip web interface: