5-264 C70 Capacitor Bank Protection and Control System GE Multilin5.9 TRANSDUCER INPUTS AND OUTPUTS 5 SETTINGS55.9.3 DCMA OUTPUTSPATH: SETTINGS TRANSDUCER I/O DCMA OUTPUTS DCMA OUTPUT F1(U8)Hardware and software is provided to generate DCmA signals that allow interfacing with external equipment. Specific hard-ware details are contained in chapter 3. The DCmA output channels are arranged in a manner similar to transducer input orCT and VT channels. The user configures individual channels with the settings shown below.The channels are arranged in sub-modules of two channels, numbered 1 through 8 from top to bottom. On power-up, therelay automatically generates configuration settings for every channel, based on the order code, in the same manner usedfor CTs and VTs. Each channel is assigned a slot letter followed by the row number, 1 through 8 inclusive, which is used asthe channel number.Both the output range and a signal driving a given output are user-programmable via the following settings menu (an exam-ple for channel M5 is shown).The relay checks the driving signal (x in equations below) for the minimum and maximum limits, and subsequently re-scales so the limits defined as MIN VAL and MAX VAL match the output range of the hardware defined as RANGE. The follow-ing equation is applied:(EQ 5.26)where: x is a driving signal specified by the SOURCE settingImin and Imax are defined by the RANGE settingk is a scaling constant calculated as:(EQ 5.27)The feature is intentionally inhibited if the MAX VAL and MIN VAL settings are entered incorrectly, e.g. when MAX VAL – MINVAL < 0.1 pu. The resulting characteristic is illustrated in the following figure.Figure 5–123: DCMA OUTPUT CHARACTERISTIC DCMA OUTPUT F1DCMA OUTPUT F1SOURCE: OffRange: Off, any analog actual value parameterMESSAGE DCMA OUTPUT F1RANGE: –1 to 1 mARange: –1 to 1 mA, 0 to 1 mA, 4 to 20 mAMESSAGE DCMA OUTPUT F1MIN VAL: 0.000 puRange: –90.000 to 90.000 pu in steps of 0.001MESSAGE DCMA OUTPUT F1MAX VAL: 1.000 puRange: –90.000 to 90.000 pu in steps of 0.001I outI min if x MIN VAL<I max if x MAX VAL>k x MIN VAL–( ) I min+ otherwise=k I max I min–MAX VAL MIN VAL–-------------------------------------------------=842739A1.CDRDRIVING SIGNALOUTPUT CURRENTMIN VALI minI maxMAX VAL
