Issue
- Xenta Repeater offers signal restoration and conditioning on LON networks
- Lon communication issues
- Completion-event failures
Environment
- Vista Lon Networks
- Xenta Repeaters (Part # 007309120)
Cause
Lon Networks can suffer communications problems due to the physical length of the network and / or due to the number of devices on the network. A Xenta Repeater can help to resolve these problems and allow for a longer physical communications network and a larger number of devices to be used.
Resolution
A Xenta Repeater is a device that uses a standard Xenta 400 base and is installed in the middle of the Lon network channel and separates it into two segments. (Note: Lon channels are sections of a Lon network that are separated by a router while segments are sections of a channel that have divided using a repeater.)
One segment of the Lon channel is connected to either of the pairs of COM 1 terminals and the other segment is connected to either of the pairs of COM 2 terminals. Each Lon segment must stay within the recommended length limits as seen below:
| Cable | Max. bus length, doubly terminated bus topology (m)/(ft) | Max. node-to-node length, singly term. free topology (m)/(ft) | Max. length, singly terminated free topology (m)/(ft) | |||
| Belden 85102, single twisted pair | 2,700 | 8,858 | 500 | 1,640 | 500 | 1,640 |
| Belden 8471, single twisted pair | 2,700 | 8,858 | 400 | 1,312 | 500 | 1,640 |
| UL Level IV 22AWG, twisted pair | 1,400 | 4,593 | 400 | 1,312 | 500 | 1,640 |
| Siemens J-Y(st)Y 2x2x0.8 4-wire helical twist, solid, shielded | 900 | 2,953 | 320 | 1,050 | 500 | 1,640 |
| TIA568A Cat.5 24AWG, twisted pair | 900 | 2,953 | 250 | 820 | 450 | 1,476 |
The following rules must be adhered to:
- A maximum of 128 devices can be placed on a Lon channel
- A maximum of 64 devices can be placed on a Lon segment
- A channel may use up to 2 repeaters creating a maximum of 3 segments
If a router is not being used on a channel then there may only be 64 devices on that channel since the channel is made up of only one segment.
It is recommended to limit the number of devices per segment to 50 when engineering a Lon network. This will allow for some devices to be added or re-distributed as needed during installation.
The Xenta Repeater consists of two internally connected Lon transceivers, each with a transient suppression circuit.
Data packets are picked up by the transceiver on one segment and re-broadcast onto the next segment using the second transceiver. Only Lon packets are read and re-broadcast rather than simply amplifying the signal along with all of the noise on the network. This provides for a strong, clean and noise-free signal on either side of the Xenta Repeater.
