Product data

DeltaV Product Data Sheet
October 2014 – Page 23 S-Series Electronic Marshalling
Discrete Input 24 VDC low-side sense (dry contact) CHARM
Specifications for DI 24 VDC low-side sense (dry contact) CHARM
Sensor Types 24 VDC Dry Contacts
Detection level for On
> 2.25 mA (<5.3 kΩ)
Detection level for Off
< 1.75 mA (>8.2 kΩ)
Channel Impedance
4.8 KΩ
Wetting Voltage 22.5Volts (± 5%), current limited to 12.5 mA nominal
Fault Detection capable
field resistor pack (optional)
• Guaranteed short circuit: <100 Ω
• Guaranteed good status: 400 Ω to 40 kΩ
• Guaranteed open circuit: > 75 kΩ
Configurable channel types:
• Discrete input
• Pulse Count
Dry contact or discrete state sensor changing <2 Hz
Pulse train 0.1 Hz to 10 KHz, 50 µsec min pulse width
Field Circuit Protection - 12.5 mA Current Limiting Circuit
- Field wiring disconnect
CHARM power req. 22 mA max @ 24 VDC
CHARM Heat Dissipation 0.33 W
Simplified Circuit and Connection Diagram for DI 24 VDC low-side sense CHARM