Siemens Simatic S7-400

Time switch based on the S7-300/400 CPUs with simple HMI system
including radio-controlled clock connection
Rev. B - final 19.07.2002 35/84
Copyright © Siemens AG 2005 All rights reserved
BID21669756_Zeitschaltuhr_einfach_DOKU_v20_e.doc
Basic data/parameterizability:
RAM requirements:
year: 1110 bytes
Instance DB: 56 bytes
The parameter “Time_To_Check“ is a structure of the “year_udt“ (UDT4)
type. It contains:
• Start month
• Start day
• Start hour, start minute, start second summarized as “starttime” with
structure of the “times” (UDT6) type
• End month
• End day
• End hour, end minute, end second summarized as “endtime” with
structure of the “times” (UDT6) type
4.3.6 Relative time switch
The module for relative time switching has the following input parameters:
• EnableClock of “BOOL“ type
Value = 1: Clock enabled
Value = 0: Clock not enabled
• Reset of “BOOL“ type
Value = 1: Each positive edge is evaluated at the parameter “StartTime“
-> the time is restarted every time
Value = 0: The first positive edge at the parameter “StartTime” is
evaluated. If the time has elapsed, the clock can be restarted by another
edge change at the input “StartTime”.
• The parameter “Time_To_Go“ is a structure of the “relative_udt“ (UDT5)
type. It contains:
- Number of days
- Number of hours
- Number of minutes
- Number of seconds
• Reset of “BOOL“ type
Value = 1: Clock is reset
Value = 0: Clock runs in “Normal operation”
The module for relative time switching has the following in/out parameters:
• StartTime of “BOOL“ type
At a positive edge change at this parameter, the clock is active and
stays active until the time at the parameter “time_to_go“ has elapsed.