Issue
Choosing a terminator, found there were several choices (Loytec and TAC). Which one should I choose? What are the differences between them?
Environment
- Vista
- LON physical network
- FT-10
Cause
There are several types of terminators for different use in the LonWorks network.
Resolution
TAC terminators
One TAC terminator has 4 wires, however, only need to connect two wires (red or green). Red wires are used for bus topology Lon structure. And, green wires are used for free topology Lon structure.
TAC terminators can only be used in FT-10 (78kbps) LonWorks network. In addition, one TAC terminator can only connect to ONE end of a channel. Which means, a channel without a repeater, you need TWO TAC terminators, and a channel with a repeater, you need FOUR TAC terminators.
Note: To test an end of the line resistor (EOL), take a reading of the capacitance across the leads (either the two green or two red leads). You should read somewhere around 50 uF.
LOYTEC terminators (L-term)
For LonWorks networks, Loytec has 3 different types of terminators: LT-03, LT-13, and LT-33.
LT-03: One network terminator for TP/FT-10 channel (bus or free topology), similar to TAC terminators.
LT-13: One network terminator for TP/FT-10 channel (bus or free topology), and one network terminator for TP/XF-1250 channel (bus or free topology). Barely used in TAC Vista system.
LT-33: Two network terminators for TP/FT-10 channel (bus or free topology). One connection is on the top, and one is at the bottom. Since you cannot separate two connections, most likely it is used before and after a repeater.
