Warning
Electrostatic Discharge Required: Always discharge static electricity from your person by touching metal prior to handling any hardware. Failure to do so may result in damage to devices.
Issue
Proper configuration of supervised inputs, Mercury IO modules (i.e MR52) versus Continuum IO modules (AC1/AC1Plus) for transitioned Continuum sites.
Product Line
EcoStruxure Access Expert
Environment
- Access Expert Controller
- Access Expert Reader Interface
- Access Expert Premise Software
- Access Expert Hosted Software
- Continuum AC-1 IO Module
Cause
Guidance is needed on the proper configuration of Access Expert custom EOL resistor tables in order to achieve full supervision of inputs associated with readers/doors.
Full supervision in this context means not only being able to detect normal input operation (activation/deactivation) but also detection of attempts to tamper with the input's circuit (short circuit, open circuit, grounding, the introduction of foreign voltages, etc.)
Please note that not all resistor configurations can detect all the various circuit issues, for example, a NO Series resistor configuration can't detect a cut in the wire given that the open circuit is the normal state for the Deactivated value of the input.
The resistor configuration that provides the most supervision is the Series/Parallel configuration, using 2 resistors is possible to detect both short and open circuits.
Resolution
Continuum supported a fixed 10K Ohms resistance for supervised inputs, furthermore, Continuum IO modules (AC1/AC1Plus) transitioned to Access Expert under an AX-SSC controller continue to operate with Continuum firmware, this means that they do not support the custom EOL tables in Access Expert, the only configuration that is possible for AC1/AC1Plus modules is the mode of connection of the resistor (parallel, series or both).
Also, when using 2 resistor configuration, the placement of the resistor is different in Continuum compared to Mercury hardware
CONTINUUM
When the switch is open only the resistor on the left is seen by the input.
When the switch is closed, the two resistors are presented to the input in parallel with each other resulting in the input reading half the sum of the total resistance value.
SECURITY EXPERT
When the switch is open, the two resistors will be presented to the input in series with each other resulting in the input reading the sum of the two resistors value.
When the switch is closed only one resistor is presented to the input
For the above reasons, Continuum transitions sites where the AC1/AC1Plus has been replaced with Mercury hardware like the MR52 for example, need to configure one or more custom EOL table(s) for 10K resistors.
*** The sample tables provided below contain resistance values calculated to take into account wide variations in total supervised loop resistance due to wire distance, gauge etc., supervised loops should be installed in accordance to distance and gauge guidelines for wires as well as recommended resistor tolerance.
It may be necessary to make adjustments to the resistance values in the tables on a site by site basis.
See below sample tables for all six possible 10K resistor configurations
- Normally Open Parallel (10K-NO-P)
- Normally Closed Parallel (10K-NC-P)
- Normally Open Series (10K-NO-S)
- Normally Closed Series (10K-NC-S)
- Normally Open Series/Parallel (10K-NO-SP)
- Normally Closed Series/Parallel (10K-NC-SP)+
1. Normally Open Parallel (10K-NO-P)
2. Normally Closed Parallel (10K-NC-P)
3. Normally Open Series (10K-NO-S)
4. Normally Closed Series (10K-NC-S)
5. Normally Open Series/Parallel (10K-NO-SP)
6. Normally Closed Series/Parallel (10K-NC-SP)+
