How long should each camera cable be?
The tool measures the straight distance along the vehicle from the camera to the MDVR. It adds the extra route for that camera position and the slack at the two ends. Then it adds an allowance and rounds up to a length you stock.
Which routing allowances does the tool assume?
These are typical values for planning. Your vehicle routes differently, so measure when you can.
| Vehicle | Length | Slack at both ends | |
|---|---|---|---|
| Bus | 12m | 1.5m | typical |
| Truck | 9m | 1m | typical |
| Trailer or semi | 16m | 2.5m | typical |
| Car or van | 5m | 0.5m | typical |
| Camera | Distance from the front | Extra route | Outside the cab |
|---|---|---|---|
| Forward (ADAS) | 3% | 0.5m | No |
| Driver (DSM) | 6% | 0.5m | No |
| Left side | 50% | 1.5m | Yes |
| Right side | 50% | 1.5m | Yes |
| Rear | 100% | 1m | Yes |
| Inside the cabin or cargo area | 55% | 0.5m | No |
| MDVR position | Distance from the front | |
|---|---|---|
| Near the cab | 6% | typical |
| Middle of the vehicle | 50% | typical |
| Toward the rear | 90% | typical |
Typical values, not a Tracom specification. Replace them with what you measure on the vehicle.
How do you plan the materials for a fleet?
List the vehicle types
Group the fleet by type and length. One estimate covers every vehicle of the same type and layout.
Decide where the MDVR goes
Pick a spot with ventilation, access and protection from water. The tool measures every run from it.
Walk the route of one vehicle
Lay a string from each camera to the MDVR along the real route, around frames and through grommets. Measure the string.
Enter the vehicle and the cameras
Use the measured runs where you have them. Leave the rest at 0 and the tool uses its typical route.
Enter your cable stock
List the lengths you can buy. The tool rounds each run up to the next one and shows the offcut.
Order with spares
Take the parts list for the fleet, with the spare allowance. Keep the cut list on the job card.
Worked example
- A 9 m truck with the MDVR behind the cab and four cameras: forward, driver, left side and rear.
- Runs with the 15% allowance and the 1 m minimum: 3.5 m, 3.5 m, 7.5 m and 12.0 m. With stock of 3, 5, 8, 10, 15 and 20 m you cut 5 + 5 + 8 + 15 = 33 m per truck.
- A rear camera on a 16 m trailer needs 21.3 m. The longest stock cable is 20 m, so the tool adds a 3 m piece: 20 + 3 m with one joint.
- Ten trucks with 10% spare: 22 cables of 5 m, 11 of 8 m and 11 of 15 m, which is 363 m of camera cable, plus 66 m of power wire and 66 m of ignition wire.
Common mistakes
- Ordering by vehicle length alone. Cables go around frames and through panels, so the route is longer than the straight line.
- Forgetting the slack at the ends. The MDVR must come out of its mount for service, and the camera needs a loop.
- Skipping seals for outside cameras. A cable that enters the cab from outside needs a gland or a seal.
- Joining long runs without checking the limit. Every joint is a weak point, and the datasheet may cap the run. Move the MDVR before you join.
Assumptions and limits
The estimate rests on typical routing allowances and on the lengths you enter. It is not a survey, so check one vehicle of each type before you order. Cable type, connectors, the longest run and the number of channels come from the datasheets of your MDVR and cameras, and no default here is a Tracom specification. To plan the SD cards, use the MDVR SD card endurance estimator.