Functional Scope Of Global Functions, PSM, Function - GF54.21-D-3009H
MODEL 906 with CODE (ED5) Parameterizable special module (PSM)
MODEL 906 with CODE (ED8) Preinstallation for parameterizable special module (PSM)
Parameterizable undervoltage detection
The parameterizable undervoltage detection makes it possible to make the functions of the PSM control unit conditional on the on-board power supply voltage
The thresholds and times can be set under "Global functions/Parameters - Undervoltage".
This undervoltage detection does not cancel out the function of the hardware undervoltage detection in the PSM control unit, instead it should be seen as a configurable add-on. In the evaluation of the on-board power supply voltage the system always falls back on the higher of the two voltage values which are applied to the 2 circuit 30 connections of the PSM control unit.
This ensures that undervoltage detection remains functional even if one of the connections fails.
3 modes are established for global undervoltage (see picture, page 3):
- "Normal"
- "Undervoltage detected"
- "Undervoltage aborted"
In the "Undervoltage detected" mode, only the "PSM signal:
Undervoltage detected" signal is set to "1" in the signal pool. The functions or outputs parameterized according to the undervoltage are only deactivated in the "Undervoltage aborted" mode. The voltage thresholds as well as times for the switchover between the various modes can be parameterized.
Here, 0 s can, of course, also be specified for the times (e.g. between "Undervoltage detected" and "Undervoltage aborted"). The signals listed in the following table are generated.
| Signal | Remarks |
|---|---|
| "Abort due to parameterized undervoltage" | Set if the status changes following "Undervoltage aborted". Used as a condition in the case of outputs with parameterizable dependence on the vehicle status. |
| "Parameterized undervoltage detected" | Set if the status changes following "Undervoltage detected". Can be parameterized, for example, as a setting condition for the Controller Area Network bus class B (interior) (CAN-B) signal "PSM signal: Undervoltage detected". |
The correlations for detection of the global undervoltage and the different effects on the PSM control unit are shown in the following status diagram.
Parameterizable run-on time
In the parameter set "Global functions/Parameters - PSM run-on time", the run-on time of the PSM control unit can be set in minutes. If "0" is set, the run-on is deactivated. The run-on time progresses when the vehicle is locked via the transmitter key. If the vehicle is unlocked, the run-on time is reset to the parameterized value.
After the expiration of the parameterized run-on time the PSM control unit can change to rest mode, if it is not kept awake by other conditions, e.g. individual discrete outputs are active.
During the run-on time, all functions of the PSM control unit can still be operated, provided that they do not require information from CAN-B.
Parameterizable keeping awake function
The PSM control unit can be kept awake via the application "Parameterization" with the aid of this function module.
Thus it is possible to prevent a rest mode of the PSM control unit although all the internal conditions required for this are met. This is important in the case of functions that require a continuously active PSM control unit and for which the time limit for the normal run-on of the PSM control unit is not sufficient.
In the event of an incorrect application the PSM control unit cannot change to rest mode, this leads to an increased quiescent current.
To activate the function, it is necessary to set the "Internally wake PSM" parameter in the parameter set "Global functions/Parameters - Internally wake" to "ACTIVATED".
After this the function can be switched on with an arbitrary bit signal from the signal pool (e.g. programmable logic controller (SPS) output, discrete input).
For this purpose, you must assign the appropriate signal to the "Internally wake PSM" parameter.
| Parameterizable special module (PSM) control unit component description | GF54.21-D-5005H |