Alcorn Mcbride V+ series, User Manual

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14-8 SMPTE Machine Hardware Reference
Voltage Inputs vs. Contact Closures
There are many advantages to using Voltage Inputs over Contact Closures.
First, a Contact Closure can only be located a short distance from the SMPTE
Machine. Second, Contact Closures use the SMPTE Machine’s own power
supply, so external wiring errors can damage the entire unit.
Figure 1 – Contact Closure Schematic.
Figure 2 – Voltage Input Schematic.
Configuration Maximum Distance
Contact Closures 10ft
Voltage Inputs Limited only by wire gauge
Table 11 – Voltage Inputs are advantageous for many reasons, including the distance at
which they are operational.