Installation manual

FuelMaster

Installation Manual

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i. Controlling Carwashes, Gate Openers. There are some devices which may be controlled by

simple contact closure switching, but do not have pulse emitters. Under normal operating

conditions, if an FMU provides an authorization signal but does not receive pulses, it will shut the

hose position down through Zero Quantity Transaction Limits, a safety feature built into the FMU

to prevent continual authorization when no pulses are received.

Carwashes, gate openers, and similar devices do not (and cannot) generate pulses. They cannot

be controlled like a typical dispensing device which is expected to send pulses to the FMU.

Except for AIM2™, carwashes and gate openers are activated through the use of a Smart Relay

Assembly. The Smart Relay Assembly provides a programmable momentary activation signal,

and generates pulses to prevent zero quantity shutdowns. AIM2™ FMUs do not require a Smart

Relay Assembly to activate a carwash or gate opener.

Devices which do not have pulse emitters may be controlled by either of two methods: 1) with a

Smart Relay Assembly, or 2) with an AIM2™ controlling access point. In the absence of an FMU-

3500 access point, control must be through a Smart Relay Assembly. The AIM2™ access point

is covered in the AIM2™ Installation Manual.

The Smart Relay Assembly (see Figure 4-11) is an option purchased for the purpose of using an

FMU to control carwashes, gate openers, and other similar devices which do not generate

pulses. The Smart Relay Assembly may be added as a first or second relay assembly in an

FMU. A Smart Relay Assembly may control a maximum of three devices. Where it has four

relays, three relays are used for control and the fourth relay is used to generate pulses. Each

relay activation generates 10 pulses, which is translated to one transaction.

Smart Relay Assemblies have Programmable Interface Controllers (PICs) programmed for the

Figure 4-13. Location of 75K ohm Pump Handle Detect Resistors

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