Compact Utility Outstation with 24IO and serial ports

Real time clock

RTU870

The real time clock can be used in the application programme to start /stop or do any other time function related to the control or to the monitoring of the application. The real time clock and the time base is available in a number of internal registers (BM10 to BM 17). Power supply block diagram (type 60) Typical charge / discharge cycle (type 60) Power monitor
+24V(20-28V) 0 +5V+12V & + 5VReg. 12V Reg. RegisterContentRangeRemarks
Expan-sion >20V>24V 110V-240V>100V µ C BM10Seconds0-59 BM11Minutes0-59 BM12Hours0-23
Externalbattery BatteryOKMainsOK BM13Week day1-71=Monday, 7= Sunday BM14Date1-31 A mains indicator informs the CPU that mains supply is applied. If themains supply should fail or go lower than accepted by the power supply, a status flag (m9.7) indicates the fault to the application program, which may issue a warning by making a dial-up or by setting a local output. Battery low voltage warning is also given when the battery is discharged to approximately 20% of its capacity (22.0V). The indicator returns to normal when battery is charged to approximately 80% of its capacity . The indicator (m9.6) allows the CPU and the application programme to issue a warning and close down before loosing operation. The close down procedure may include a controlled shut down sequence of the process and an emergency alarm to the central monitoring station. To prevent damaging the battery by deep discharge, the battery will automatically be disconnected and the operation will stop, without any further warning, if the battery voltage goes below 20.8V.The battery ON/OFF signal enables the CPU to disconnect the battery,for a short period, during operation in order to test the battery. Due to the fact that the output of the charger has a higher open circuit output voltage than the battery voltage, it is not possible to detect a missing battery without disconnecting the battery from the charger. When mains is applied the battery is disconnected shortly from the charger at start-up and hereafter every 24 hours (00:00) to check the battery voltage. If low or missing battery is detected the battery will be checked every 10 second until the voltage is back to normal (>24V). BM15Month1-12 BM16Year0-99 It is possible to monitor the condition of the external lead acid battery and the mains supply in the application programme. Time base The time base will typically be utilised to trigger the log elements in order to facilitate cyclic logging and they may also be used to trigger other functions related to the actual application. RegisterTime interval M17.00.1 second M17.11 second M17.210 second M17.31 minute M17.410 minute M17.51 hour M17.610 hour M17.7not usedThe output of the time base is active only for one scan in the applicationprogramme (e.g. 100 ms).Adjustment of time is done with an accuracy of +-1s, as the time stampand internal resolution (eg. 100ms) is generated by firmware. Supply for the micro controller and other electronics in theRTU module itself (5V). 12V for expansion modules (local bus), 8/10 pole modularjack, max 300mA. RTU Power Supply/industrial battery charger (type 60) 24V (20-28V) for digital I/O, max. 0,5A maximum, 2 pole plug-in screw terminal. The RTU are equipped with an integrated switch mode power supply and a charger circuit, able to charge and monitor an external lead acid battery. The battery can be a 3 to 12 Ahour battery, depending on the actual load and the required backup time. The actual backup time can be calculated from the average consumption of the modules installed (RTU unit and expansion module(s)) and the capacity of the battery used. As the power supply has a current limiter, the recharge time will depend on the size of the battery and the average current used for the electronic circuits.The following outputs/voltages are derived from the RTU power supply: Battery, charging current up to 0,5A, 2 pole plug-in screwterminal. 24VDC supply for serial TTY interface. The 24VDC is galvanic isolated.The maximum current supplied from the power supply to the battery andelectronic circuits is 0,5 A (24VDC). RegisterContent M9.6Battery OK M9.7Mains OK Power consumption Power consumption is directly related to the number of I/O´s connected to the RTU.The mains power supply will, until the battery is fully charged, work asa constant current source limited to 0,5A. The electronic circuits (RTU and expansion modules) will draw their required current and the remain-
Brodersen Controls A/S * Industrivej 3 * DK-4000 Roskilde * Denmark * Tel (+45) 4674 0000 * Fax (+45) 4675 7336 40068.100 / 48.05

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