Specifications

Field Control Systems
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ADVANCED CONTROL TECHNOLOGIES
Decoders
MAXIMUM CRITICAL PATH LENGTHS FOR TWOWIRE PATHS
Nominal Wire Size
ohms/1000'
ohms/Km
MAXIMUM LENGTH FOR CRITICAL PATH
LOOP STAR
Km Miles Km Miles
2.5 mm  15.00 ohms/Km 12.0 7.5 3.0 1.8
14 AWG 2.58 ohms/1000' 15.2 9.6 3.8 2.4
12 AWG 1.62 ohms/1000' 24.4 15.2 6.1 3.8
10 AWG 1.02 ohms/1000' 39.2 24.4 9.8 6.1
MAXIMUM WIRE LENGTHS FOR
SECONDARY PATH WIRE RUNS
Wire Size
SECONDARY WIRE RUN LENGTHS
Meters Feet
1.5 mm  100 328
2.0 mm  133 436
2.5 mm  166 545
16.0 AWG 88 289
14.0 AWG 139 456
12.0 AWG 220 720
CHARACTERISTIC TABLE FOR VARIOUS DECODER MODELS
DECODER MODEL
NUMBER OF ADDRESSES
PER DECODER
MAXIMUM NUMBER OF
SOLENOIDS PER ADDRESS
MAXIMUM ADDRESSES
OPERATING AT ONCE
CURRENT DRAW
mA AT REST PER DECODER
FD-101 1 1 1 0.5 mA
FD-102 1 2 1 0.5 mA
FD-202 2 2 2 1.0 mA
FD-401  4 1 4 1.0 mA
FD-601  6 1 4 1.0 mA
DESIGN CRITERIA FOR DECODER SYSTEMS
CONDITION CIRRUS NIMBUS II STRATUS II STRATUS LT
Maximum resistance in critical path 33 ohms 33 ohms 33 ohms 33 ohms
Maximum number of addresses
per wire path 
250 250 250 200
Maximum number of addresses
per LDI
500 500 500 300
Maximum number of addresses
per SDI
200 200 200 200
Maximum number of active
solenoids per wire path
20 20 20 15
Recommended Interface unit LDI LDI LDI SDI
Maximum number of
active solenoids per
recommended interf ace 
40 40 40 15
Active solenoid current draw (mA)
Golf Black Solenoid 20 mA 20 mA 20 mA 20 mA
Golf Green Coil 20 mA 20 mA 20 mA 20 mA
“B” (white wires) 25 mA 25 mA 25 mA 25 mA
“DV” (black wires) 15 mA 15 mA 15 mA 15 mA
Hybrid system max number of
interfaces per system (LDI, SDI)
12 3 2 1
BASIC DATA FOR DECODER SYSTEM DESIGN
THE BASIC DATA FOR A DECODER SYSTEM IS AS FOLLOWS:
500 maximum Decoder addresses per LDI interface unit
200 maximum Decoder addresses per SDI interface unit
40 maximum Active solenoids per LDI (with 20 mA current draw each)
15 maximum Active solenoids per SDI (with 20 mA current draw each)
20 maximum Active solenoids per two-wire path on LDI (with 20 mA current draw each)
15 maximum Active solenoids per two-wire path on SDI (with 20 mA draw current each)
9 Volts Maximum allowable voltage drop per two-wire path
15 mA (total) For LDI or SDI Lights
0.5 mA each For each inactive FD-101 or FD-102 decoder
1.0 mA each For each inactive FD-401, FD-202 or FD-601 decoder
15 mA each For each active DV solenoid coil with black wires
20 mA each For each active Golf (green) solenoid coil
25 mA each For each active B solenoid coil with white wires
LSP-1 Installation No more than 8 decoders between two LSP-1 surge arrestors or no more than 500 ft.,
whichever is less. LSP-1 ground grid resistance of 50 ohms or less is recommended.
 Has LSP-1 surge protection built-in.
 A wire path is the leg coming off the LDI, SDI or LTB.
 The number of decoders on a large system with long wire runs may reduce the number of active decoders that you
will be able to operate at one time before the interface maximum current draw is exceeded and the interface shuts
down (disconnects from the field wiring).
 Although the LDI can handle a maximum of 500 decoder addresses total. With any number over 380, the number of
active decoders you will be able to operate simultaneously may be reduced.
 Although the LDI and SDI can supply 1,000 mA and 500 mA respectively, allow 50 mA of safety factor
(design 950 mA with a LDI and 450 mA with a SDI)