5-304 L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUALINPUTS/OUTPUTS CHAPTER 5: SETTINGS55.9 Inputs/outputs5.9.1 Contact inputsSETTINGS INPUTS/OUTPUTS CONTACT INPUTSA contact inputs and outputs are digital signals associated with connections to hard-wired contacts. Wet and dry contactsare supported.The contact inputs menu contains configuration settings for each contact input as well as voltage thresholds for eachgroup of four contact inputs. Upon startup, the relay processor determines (from an assessment of the installed modules)which contact inputs are available and then display settings for only those inputs.An alphanumeric ID can be assigned to a contact input for diagnostic, setting, and event recording purposes. The CONTACT IPX On (Logic 1) FlexLogic operand corresponds to contact input “X” being closed, while CONTACT IP X Off corresponds to contactinput “X” being open. The CONTACT INPUT DEBNCE TIME defines the time required for the contact to overcome ‘contactbouncing’ conditions. As this time differs for different contact types and manufacturers, set it as a maximum contactdebounce time (per manufacturer specifications) plus some margin to ensure proper operation. If CONTACT INPUT EVENTS isset to “Enabled,” every change in the contact input state triggers an event.A raw status is scanned for all Contact Inputs synchronously at the constant rate of 0.5 ms as shown in the followingfigure. The DC input voltage is compared to a user-settable threshold. A new contact input state must be maintained for auser-settable debounce time in order for the L30 to validate the new contact state. In the following figure, the debouncetime is set at 2.5 ms; thus the 6th sample in a row validates the change of state (mark no. 1 in the diagram). Once validated(de-bounced), the contact input asserts a corresponding FlexLogic operand and logs an event as per user setting.A time stamp of the first sample in the sequence that validates the new state is used when logging the change of thecontact input into the Event Recorder (mark no. 2 in the figure). CONTACT INPUTS CONTACT INPUT H5a CONTACT INPUT H5a ID:Cont Ip 1Range: up to 20 alphanumericcharacters CONTACT INPUT H5aDEBNCE TIME: 6.0 msRange: 0.0 to 16.0 ms in steps of 0.5 CONTACT INPUT H5aEVENTS: DisabledRange: Disabled, Enabled↓ CONTACT INPUT xxx CONTACT INPUT THRESHOLDS Ips H5a,H5c,H6a,H6cTHRESHOLD: 33 VdcRange: 17, 33, 84, 166 Vdc Ips H7a,H7c,H8a,H8cTHRESHOLD: 33 VdcRange: 17, 33, 84, 166 Vdc↓ Ips xxx,xxx,xxx,xxxTHRESHOLD: 33 VdcRange: 17, 33, 84, 166 Vdc
