© 2022 All rights reserved. Data subject to change without notice.
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Rev. B | 2022.03
LPT-M - Operation Manual
To ensure robust data communications, a daisy chain wiring configuration
must be used. This means, four wires run from one end of the digital network to
the other, through the same connections along the entire run. From one digital
device to the next digital device, A goes to A; B goes to B; GND goes to GND;
24V goes to 24V. Each CETCI digital device has two RS‐485 terminal blocks to
make wiring easier. Use one terminal block for incoming wires and the other
for outgoing wires. It does not matter which RS‐485 terminal block is used for
incoming or outgoing wires, just make sure the four incoming wires are wired to
one terminal block and the four outgoing to the other terminal block. Do not mix
up the individual wires or the two groups of four wires.
NOTE: WARRANTY VOID IF SOLID-CORE WIRE IS USED AT THE WIRING
TERMINAL STRIP.
When using solid core wiring for distribution (in the conduit), use stranded wire
pigtails 18 AWG within the enclosure to connect to the circuit board. The rigidity
of solid-core wire can pull a soldered terminal strip completely off a circuit
board and this will not be covered under warranty.
An end of line jumper must be installed at both ends of the digital network. To
terminate, you must place a 120 ohm resistor on the IN (or sometimes labelled
EN) termination jumper position ON the TERM jumper bank on the FIRST
DIGITAL DEVICE (which might not be the Controller) and the LAST DIGITAL
DEVICE in the wire run. The termination resistor jumper on all other digital
devices in the network should be in the disabled position. Every CETCI digital
device has a termination resistor jumper. The factory default setting of the
termination resistor on all digital devices disabled.
5.7.1 Power & Output Connections
If the LPT-M is being connected to either a QCC or FCS the supply voltage will
either be supplied by the QCC or FCS and any additional power requirements of
the system will be supplied by RPS-24VDC Remote Power Supply devices. If the
LPT-M is being used on systems other than a QCC or FCS then either 24 VDC
