5-306 D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUALINPUTS/OUTPUTS CHAPTER 5: SETTINGS55.9.3.2 Latching outputsSETTINGS INPUTS/OUTPUTS CONTACT OUTPUTS CONTACT OUTPUT H1aThe latching output contacts are mechanically bi-stable and controlled by two separate (open and close) coils. As suchthey retain their position even if the relay is not powered up. The relay recognizes all latching output contact cards andpopulates the setting menu accordingly. On power up, the relay reads positions of the latching contacts from the hardwarebefore executing any other functions of the relay (such as protection and control features or FlexLogic).The latching output modules, either as part of the relay or as individual modules, are shipped from the factory with alllatching contacts open. It is highly recommended to double-check the programming and positions of the latching contactswhen replacing a module.Since the relay asserts the output contact and reads back its position, it is possible to incorporate self-monitoringcapabilities for the latching outputs. If any latching outputs exhibits a discrepancy, the LATCHING OUTPUT ERROR self-testerror is declared. The error is signaled by the LATCHING OUT ERROR FlexLogic operand, event, and target message.OUTPUT H1a OPERATE — This setting specifies a FlexLogic operand to operate the ‘close coil’ of the contact. The relay seals-in this input to safely close the contact. Once the contact is closed and the RESET input is logic 0 (off), any activity of theOPERATE input, such as subsequent chattering, does not have any effect. With both the OPERATE and RESET inputs active(logic 1), the response of the latching contact is specified by the OUTPUT H1a TYPE setting.OUTPUT H1a RESET — This setting specifies a FlexLogic operand to operate the ‘trip coil’ of the contact. The relay seals-inthis input to safely open the contact. Once the contact is opened and the OPERATE input is logic 0 (off), any activity of theRESET input, such as subsequent chattering, does not have any effect. With both the OPERATE and RESET inputs active (logic1), the response of the latching contact is specified by the OUTPUT H1a TYPE setting.OUTPUT H1a TYPE — This setting specifies the contact response under conflicting control inputs; that is, when both theOPERATE and RESET signals are applied. With both control inputs applied simultaneously, the contact closes if set to“Operate-dominant” and opens if set to “Reset-dominant.”Figure 5-178: Contact input/output module type 4L contact 1 logicApplication example 1A latching output contact H1a is to be controlled from two user-programmable pushbuttons (buttons number 1 and 2). Thefollowing settings are applied. CONTACT OUTPUT H1a OUTPUT H1a IDL-Cont Op 1Range: up to 20 alphanumeric characters OUTPUT H1a OPERATE:OffRange: FlexLogic operand OUTPUT H1a RESET:OffRange: FlexLogic operand OUTPUT H1a TYPE:Operate-dominantRange: Operate-dominant, Reset-dominant OUTPUT H1a EVENTS:DisabledRange: Disabled, Enabled
