Siemens RVD240 - Page 8

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Siemens Building Technologies Basic documentation RVD240 CE1P2384en
HVAC Products Contents 27.05.2004
20.2.1 Addressing the devices..................................................................................76
20.2.2 Source of time of day .....................................................................................76
20.2.3 Bus power supply...........................................................................................77
20.2.4 Outside temperature source ..........................................................................77
21 Locking signals ..............................................................................................78
21.1 Fundamentals ................................................................................................78
21.2 Critical locking signals....................................................................................78
21.3 Uncritical locking signals................................................................................78
21.3.1 General ..........................................................................................................78
21.3.2 Controller-internal uncritical locking signals...................................................79
21.3.3 Uncritical locking signals from the data bus...................................................79
22 Function block Device functions ....................................................................80
22.1 Operating lines...............................................................................................80
22.2 Actuator pulse lock.........................................................................................80
22.3 Frost protection for the plant ..........................................................................80
22.3.1 Principle .........................................................................................................80
22.3.2 Mode of operation with outside sensor ..........................................................80
22.3.3 Mode of operation without outside sensor .....................................................81
22.3.4 Frost protection for the heating circuit flow ....................................................81
22.4 Flow alarm .....................................................................................................81
22.4.1 Heating circuit and d.h.w. circuit with storage tanks ......................................81
22.4.2 Direct d.h.w. heating via heat exchanger.......................................................82
22.5 Winter- / summertime changeover.................................................................83
23 Function block M-bus parameter ...................................................................84
23.1 Operating lines...............................................................................................84
23.2 General ..........................................................................................................84
23.3 Addressing and identification .........................................................................84
23.4 Baud rate .......................................................................................................84
23.5 Load management .........................................................................................84
23.5.1 Load management of d.h.w. ..........................................................................84
23.5.2 Load management of the heating system......................................................84
23.5.3 Resetting the load control signals ..................................................................85
23.5.4 Use on the LPB..............................................................................................85
23.5.5 Resolution of M-bus signals...........................................................................85
24 Function block PPS parameter ......................................................................86
24.1 Operating lines...............................................................................................86
24.2 Suitable devices.............................................................................................86
24.3 Impacts of a room unit on the heating circuits ...............................................86
25 Function block Test and display.....................................................................87
25.1 Operating lines...............................................................................................87