Timer/Counter Memory - Siemens SIMATIC 505 User Manual

Simatic 505 SoftShop

Timer/Counter Memory

A block of memory within the controller is reserved for the operation of
the timer/counter group of RLL instructions, including the following:
Timer (TMR, TMRF)
Discrete Control Alarm
Timer(DCAT)
Up/Down Counter
(UDC)
When you assign a number to a timer, counter, up/down counter, or discrete/motor
control alarm timer, be sure that you do not use that number for any other timer,
counter, up/down counter, or discrete/motor control alarm timer. For example, if
you configure a Timer 6 (TMR6), do not configure any other operation, e.g., a
counter (CTR) or a discrete control alarm timer (DCAT) with the number 6.
Assigning the same number more than once could cause unpredictable operation by
the controller, which could result in death or serious injury to personnel and/or
damage to equipment.
Do not use the same reference number more than once for timer, counter, up/down
counter, and discrete/motor control alarm timer instructions.
NOTE If you use an operator interface to change the time/counter
values, the new values are not changed in the original RLL program. If
the RLL presets are ever downloaded, e.g., as the result of a complete
restart or an edit of the network containing the Timer/Counter instruction,
the changes made with the operator interface are replaced by the values in
the RLL program.
This memory type is divided into areas for storing two types of
information. This information consists of Timer/Counter Preset (TCP)
data and Timer/Counter Current (TCC) data. When you designate a
preset value for one of the instructions in this group, this value is stored
as a 16-bit word in TCP-Memory. When the instruction is actually
operating, the current time or count is stored as a 16-bit word in TCC-
Memory.
Counter (CTR)
Motor Control Alarm Timer(MCAT)
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