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Electronic Theatre Controls Inc

How many stations does a Paradigm Processor and Station Power Module support

Question

What is the correct quantity of LON-based stations a Paradigm Architectural Control Processor (P-ACP), Paradigm Station Power Module / Mk2 (P-SPM / P-SPM-E), and Paradigm Repeater Module (P-REP / P-DREP) will support? I've heard/seen conflicting answers.

Answer

The amounts for each product are listed below:

Product Station Count (pre-5.x) Station Count (5.0.1+)
P-ACP 63 63 / 128**
P-SPM-E 63 63
P-SPM 31 31
P-REP/P-DREP 31 31

ETC's implementation of the Lon bus supports a total of 64 devices, and since a P-ACP counts as a device, and is the start of the Lon bus, that leaves a maximum of 63 stations that can be connected to the Lon bus. The P-SPM-E supports the full 63 station compliment by itself, due to an increased power supply size from the original P-SPM. A P-REP or P-DREP can be added to increase wire length, but would not increase your station count because the bus already supports the maximum about of stations. The original P-SPM only supported 31 stations, so adding a P-REP increased both wire length and station count.

If you're doing the math you'll notice the the P-SPM and P-REP only equal 62, one short of the P-ACP's maximum. This is because the P-REP is the start of a second Lon bus, and must include itself against the overall count against the P-ACP, thus leaving its supported count at 31, instead of 32.

**Paradigm 5.0.1 increased the overall station count of a P-ACP from 63 to 128, however that is across all station interfaces inclusive of it's own local Lon bus, any Network Station Power Supply (NSPS), and Ethernet stations. Thus even in 5.0.1 a P-ACP still only supports 63 stations without a NSPS added to the system.