Plants should work as efficiently as possible. This saves time, money and trouble. To achieve this, you first have to be able to measure this efficiency. With most plants, this possibility is either not available or insufficient. When asked why the plant is not running properly, the answer is: “I don’t know. All what I see is that there is not enough come out at the back”
Cycletime and partcount
The number of pieces are evaluated together with the cycle time. The evaluation is done per station and type. The average cycle time and also the effective cycle time (total time in status Cycling / number of cycles) is displayed. Good and bad parts are listed separately. Also special cycles like run or with error are displayed. ↑↑↑
The status report lists and graphically displays all possible plant states for the selected period. These are in detail:
1 = No Comms
Duration in which there was no communication with the PLC
2 = E-stop
When the emergency stop button has been pressed by the operator
3 = break
4 = repair
A repair is available if the station is in a fault state and operator intervention is then detected. An intervention is e.g. an open protective door
5 = fault
An error was detected. This can be triggered by a message with a timeout or a missing state
6 = service
The station is maintained in this state
7 = stop
A stop occurs when the operator intervenes to stop the station. This can be an open protective door or a specific stop command
8 = bypass
A station can be switched to bypass when it is not in use so that the technical availability is not determined incorrectly or errors are unnecessarily displayed and logged
9 = Wait Aux
The station either waits for a feed part or for a necessary intervention by the operator
10 = Starved
The station stops because the flow of parts from the previous station is missing.
11 = Blocked
The station has stopped because the finished part cannot be picked up by the next station
12 = setup
The station automatically makes various settings. This can be with a type or tool change
13 = cycling
The station is running correctly
The fault detailed report also lists the operator stops. Likewise, not only the initial errors but also the subsequent errors are logged. This provides information on how, for example, a repair was carried out.
The operator stops are also listed in the detailed error report. Likewise, not only the initial errors but also the subsequent errors are logged. This provides information on how e.g. a repair has been carried out. ↑↑↑
By comparing several stations within a system, it is possible to identify which station is slowing down production and why. The Cycle Time and the Non Auto value are decisive here, because usually one station is too slow or has too many faults. ↑↑↑
The OEE (Overall equipment effectiveness) provides information about how well an automated plant produces. With its help, weak points can be identified and production losses minimized. It consists of the factors plant availability, performance and quality. However, these factors can only be determined correctly if the status information of the plant also reflects reality. If the basic information about the status of the plant is doubtful, the wrong screws are tightened and the investments do not work as desired.
In addition to the three factors, 4 further variables are calculated.
MTTA (Mean Time To Attend)
Average time in minutes from detection of an error until another status is detected.
This gives information about how much time passes until an error is detected and reacted to.
MTTR (Mean Time To Repair)
Average time in minutes from the start of the error with subsequent repair until the machine is running again.
This tells you how long it takes until a fault is detected and repaired.
MRT (Mean Repair Time)
Average repair time in minutes
MTBF (Mean Time Between Failures)
Average time in minutes between the occurrence of errors.
Provides information on how long a machine will run trouble-free until it has a fault again. ↑↑↑
PCM stands for Process Controlled Monitoring. This is a very powerful tool. It consists of a transmission and a reception area and has 3 basic functions. The simplest function is the logging of up to 8 values. With these values the time and the current type are logged. Another function is to receive data or commands from the server itself. This is used for example to synchronize the time of the PLC. The third function enables the communication between the systems. ↑↑↑
Systems communicate with each other worldwide
The first word in the send tray serves as a multiplex indicator and indicates what kind of function the data to be sent is. If there is a -1, the data is interpreted as a communication block for another PDM station. The server then sends this block to the destination ID. This can be any PDM station located anywhere in the world. ↑↑↑