Missing: SK-6820 Trouble Code | Fire Alarm Resource Center

What This Code Means

A device or module (such as an SLC device or a 5496, 6815, or 5815XL module) is physically connected to the system but is not being recognized by the panel.

Common Causes

1SLC loop impedance is outside the required range
2SLC loop impedance between positive and negative is less than 500 k ohms
3SLC loop resistance is greater than 50 ohms
4Module (5496, 6815, or 5815XL) is not recognized or has a communication failure

Resolution Steps

Check that SLC loop impedance is within the required range. To measure impedance, use the following procedure: Disconnect both wires from the terminal block at the panel (SLC devices can remain connected). Measure the impedance from positive to negative and from negative to positive. Both measurements should be greater than 500 k ohms. If the installation uses T-taps, test each T-tap individually. Temporarily connect the positive wire to the negative wire of the SLC loop at the point farthest from the panel (SLC devices can remain connected). Measure the impedance from positive to negative and from negative to positive wires that were disconnected from the panel in step 1. Both measurements must be less than 50 ohms. For 5496, 6815, or 5815XL modules, check the status of the module’s green LED.