Primes PROFINET - Measurement Cycle Details; Preparing the Measurement; Opening the Shutter; Determination of the Irradiation Time

PowerMeasuringModule PMM
35,0(6
49
Revision 13 EN - 02/2023
10 Measurement cycle details
The power measurement cycle includes three steps:
1. Preparing the measurement
2. Executing the power measurement
3. Evaluating the power measurement
The details of these steps are discussed below:
10.1 Preparing the measurement
The readiness of the device is subject to three conditions:
1. The shutter is open.
2. The absorber still has the capacity to absorb the energy of a measurement
3. No other measurement cycle is activated
10.1.1 Opening the shutter
The shutter is opened by a gear motor with a friction clutch. The bit “open shutter” in the command byte
issues the command to open the shutter. The gear motor requires less than 5 seconds to open the shutter
completely.
As soon as the shutter has reached the open position the “shutter open”- bit changes to the value 1 in the
“Status 1” byte. The command bit “open shutter” can then be deactivated. Closing the shutter is done in the
same way.
Command.open shutter
command.close shutter
status1.shutter open
status1.shutter is closed
Fig. 10.1: Shutter control timing diagram
Step 2 according to chapter 10.1 requires a delay time. The waiting time allows the absorber to cool down
so that a new measurement is possible. The waiting times can be found in chapter 8.5 on page41.
At step 3 according to chapter 10.1 the measuring readiness is automatically established again after the end
of the current measuring cycle.
10.1.2 Determination of the irradiation time
The irradiation time is to be determined according to the regulations stated in chapter8.6 „Calculation of the
irradiation time“ on page41.