The following recommendations should be followed when considering the installation location and mounting for FDMs.
- The cable connecting an FDM to the Enabler PCI Card should:
- be routed (as much as possible) away from sources of Electromagnetic Noise.
- for protocols using Active FDMs this connection is RS232, so should be no longer than 10 meters
- FDMs should be mounted in a case to protect them from tampering and accidental damage.
- If Lightning protection is required, this should be installed between the FDM and Enabler Card.
- Check you are using the correct Power supply for the FDM you are using. This is documented in detail in our Power Supply requirements FAQ.
Choosing a Location
FDM cards are normally mounted in the main switchboard area of the site with an RS232 connection back to The Enabler PCB in the site server PC. You will need to determine the best housing solution depending on:
- The requirements for the site (e.g. number and type of FDM cards)
- The requirements of local authorities
- Availability of power supply for FDM cards
Case Selection
Where no existing housing can be (re)used, or where separate housing is desirable then a suitable polycarbonate housing with appropriate UL ratings should be used.
These can be obtained from any component supplier such as RS or Farnell in most countries. We are aware that some integrators have used specially designed cases incorporating space for the FDM power supply.
Cable Selection
Enabler PCI to FDM
When selecting cable to connect The Enabler PCI card to FDM cards you should consider the following:
| RS232/RS485 | Cabling should be high quality, low-loss shielded communications cable as sold for RS232 applications. Recommended type for RS232 or RS485 should be 2, 3 or 5 core, fully insulated, shielded and sheathed with tinned drain wire. |
| IFSF over LON | The cabling should be Level 4, 22 AWG Network cabling or equivalent; twisted pair (stranded or solid core) with PVC outer (no shielding is required). |
FDM to Pumps
When selecting cable to connect the FDM card to the Pumps you should consider the following.
The Forecourt Distribution module has two functions depending on the type (Active or Passive).
- Active FDMs provide physical signal conversion as well as a termination and isolation point for dispenser cabling.
- The Passive FDM only provide termination and isolation points for dispenser cabling.
In either case, communications cables from EACH dispenser should be run back to the FDM. This allows each dispenser to be isolated individually in case of problems with any one dispenser.