TP303 – Operation, Maintenance and Instructions Manual
3.10
6. For the AI block, TP303 will supply the master the value of the process variable in 5 bytes. The
four first bytes in float point format and the fifth byte the status that carries information about
measurement quality.
7. When using the TOT block, is possible to choose the totalization value (Total), and also, the
integration is made considering the operation mode (Mode_Tot), where is possible to define
how the totalization can be made (only positive flow values, only negative flow values, both
values). Is also possible to reset the totalization and configure a preset value through the
parameter (Set_Tot). The reset option is very used in batch processes.
8. The watchdog condition can also be activated, where after the communication loss detection for
the slave device with the master; the equipment can change to a fail-safe condition.
How to Configure the Totalizer Block
The totalizer function block takes the input data from the transducer block, selected by channel
number, and integrates over the time. This block is normally used to totalize flow, giving total mass
or volume over a certain time, or totalize power, giving the total energy.
The totalizer function block integrates a variable (e.g. flow rate or power) in function of the time to
the corresponding quantity (e.g., volume, mass or distance). The rate unit of the Totalizer is
providing by the transducer block. Internally, the time units are converted in rate units per second.
Each rate, multiplied by the block execution time, gives the mass, volume or energy increment per
block execution.
The total is the totalized quantity. The engineering unit used in the output is the UNIT_TOT. The unit
of the output must be compatible with the unit of the input provided by the transducer by the
channel. Then, if the input the rate is mass flow (like Kg/s, g/min, ton/h) the unit of the output must
be mass (like kg, g, ton, lb, etc.).
For more details, please, see the Function Blocks Specifications.
To configure the totalizer block in offline mode, please, go to the main menu and select Device
Offline Configuration - Totalizer Block. Using this window, the user can configure the block mode
operation, selects the channel, totalizer mode and unit for the total:
Figure 3.7 - Simatic PDM - Online Configuration - Basic Settings for Totalizer Block
Choosing the Advanced Settings window, the user can set alarm and warning limits, as well the fail-
safe condition:
the block mode.
the channel value.
conditions for
totalization and the
unit.
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