Part 1

GF54.21-D-3007HA Functional Scope Of Engine, PSM, Function

- with CODE (ED5) Parameterizable special module (PSM) working speed control


- with CODE (ED8) Preinstallation for parameterizable special module (PSM) working speed control

Engine functions
The PSM control unit provides the possibility of influencing functions in the engine control unit.
For this the parameterizable function module working speed control has been implemented which ensures the correct operation of the engine control unit.







Working speed control (including fixed speed and hand throttle actuator)
28 Signal "Working speed control request (PTO/internal)"
32 Signal "Working speed control enable (internal)"
33 Signal "Time frame for function enable expired"
34 Signal "Waiting time after clutch closing expired"
35 Signal "rpm enable (discrete/Controller Area Network bus Class C (body manufacturer) (body manufacturer CAN))"
36 Signal "Torque limit and vehicle speed limit (CAN B)"
37 Signal "Rpm limitation and fixed speed enable"
38 Signal "Rpm limitation 1 to 3 (discrete/body manufacturer CAN)"
39 Signal "Maximum rpm limit (CAN B)"
40 Signal "Minimum rpm (internal)"
41 Signal "Maximum rpm (internal)"
42 Signal "Fixed speed specification"
43 Signal "Rpm change requested (discrete/body manufacturer CAN)"
44 Signal "Cruise control: increase, reduce, resume motor speed (CAN B)"
45 Signal "Specified motor speed (CAN B)"
46 Signal "Change mode"
47 Signal "Actuation duration"
48 Signal "Hand throttle actuator speed (internal)"
49 Signal "Hand throttle actuator (discrete/body manufacturer CAN)"
DZA Change of motor speed
DZB rpm limitation
FDZ Fixed speed
FDZ&DZB Fixed speed and rpm limitation enable
HFG Hand throttle actuator
SOR Stage or ramp mode

The PSM control unit can activate the output of rpm limits, torque limits and speed limits (GB) via discrete inputs or body manufacturer CAN signals.
The following conditions must be fulfilled for this function:
- Function module "Limits" active (parameter)
- Circuit 15 ON
- Working speed control not active

Once these conditions are met, then the output of limits can be activated with the discrete or body manufacturer CAN outputs. Working speed control enables the body manufacturer (ABH) to adjust the motor speed.

Function "Working speed control"
The actual speed of the engine can be regulated via the working speed control function.
On the one hand several fixed rpm can be specified, on the other hand the rpm can also be freely adjusted via buttons.
For safety reasons, the working speed control function can only be used on a stationary vehicle with the hand brake applied.

Adjustment can be performed in the following ways:
- Selection of a fixed speed
- Analog specification of the motor speed via a hand throttle actuator
- Connection of a 2-stage switch (ADR button) to increase or reduce rpm
- Use of a cruise control switch to increase, reduce or resume rpm
- Use of body manufacturer CAN for direct specification of rpm
- Use of body manufacturer CAN to increase, reduce or resume rpm

The working speed controls ensure that sudden changes in rpm or exceeding the parameterized minimum and maximum rpm are not possible. In the event of a fault, the system attempts to set the lowest possible motor speed (idle speed) or to completely deactivate working speed control.

With working speed control, the following input conditions can be parameterized for internal function enable:
- Signal settings
- "Tml. 15 ON" and normal voltage (fixed)
- Transmission in neutral
- Engine at idle speed
- Hand brake applied (querying of this condition cannot be deactivated)
- Brake operated
- Clutch depressed or fully depressed
- Freely parameterizable Controller Area Network (data bus/ CAN bus) (CAN) signal is valid

- Properties to be parameterized
- Function module "Working speed control" activated
- Vehicle speed = 0 km/h (querying of this condition cannot be deactivated)
- Waiting time after "Clutch depressed" expired
- Waiting time for function enable expired

Once these conditions are met, the internal function enable can be activated discretely with the outputs of the working speed control request or via the body manufacturer CAN.
If the internal function enable has been activated, the motor speed specification in the PSM control unit can be output and changed. The possibilities for changing the motor speed are listed below in the order corresponding to their priority (fixed speed, hand throttle actuator, increase, reduction or resumption).

Fixed speed specification
3 different fixed speeds can be output by means of outputs (discretely or via body manufacturer CAN). Each fixed speed can be assigned a run-on time of up to 25.5 s. If a fixed speed is selected, it is approached using a ramp. If no fixed speed is selected then the lower rpm limit of the working speed control is approached with a ramp when none of the other rpm changes is active.

Hand throttle actuator
The hand throttle actuator can either be operated via an analog input (input 07 or 08) of the PSM control unit or via the body manufacturer CAN (output "Hand throttle actuator value from the body CAN bus").
In both cases, the motor speed is bounded by the parameterized limits (minimum and maximum) of the hand throttle actuator.
To activate the hand throttle actuator the accelerator pedal module must be in a rest position and the motor speed must be in a stable condition.

If an analog input is used, it is possible to activate and deactivate the hand throttle actuator via the signal setting "Input signal for activation of hand throttle actuator".
When the hand throttle actuator is activated, a ramp is initially used to approach the set motor speed. When this motor speed has been reached, the changes made at the hand throttle actuator are forwarded directly.

Use commercially available hand throttle actuators, like those used for Mercedes-Benz trucks. Use a high-side output of the PSM control unit as a power supply for this hand throttle actuator. Failure to do so may result in severe fluctuations in motor speed.

SOR
This operating mode has the lowest priority and can therefore only be used when neither the fixed speed nor the hand throttle actuator are active.
The input sources are either the cruise control switch, discrete inputs at the PSM control unit or signals from the body manufacturer CAN. The functions are "Increase motor speed", "Reduce motor speed" and "Resume motor speed".
The rpm changes know 2 operating modes, the step mode and the ramp mode.
In the stage mode, the motor speed is reduced or increased by the parameterized stage height each time an input is actuated. If the input remains actuated, the system changes to ramp mode. A ramp with the parameterized ramp slope is then output. This ramp stops either when a motor speed limit is reached or when actuation of the input is canceled.

Pulse-mode and ramp-mode resumption
The rpm resume functions similar to a cruise control. If this input is actuated, a previously stored motor speed is approached again.
This is done using a ramp.
The motor speed is stored each time an input used for increasing or reducing the motor speed (in stage or ramp mode) is actuated. If working speed control is deactivated and reactivated, the current motor speed is adopted as the new start value. Actuating the resumption function sets the original motor speed again.

The value for resume is only stored until the PSM control unit changes to rest mode (e.g. if the vehicle is parked for a longer period). The value is stored for as long as the state "Tml. 15 ON" exists.

Parameters for "Working speed control" function

Working speed control request from discrete input
Discrete request for activation of the working speed control enable. If an unfulfilled condition for activation of working speed control is detected when this input is actuated, an event entry is made (950D).
The freeze frame data for the event contains the information indicating which conditions are not yet fulfilled.
Parameterization possibilities:
Any signal Any signal can be used here.
Permanent LOW Function deactivated
(signal ID 1000)

Working speed control request from body manufacturer CAN
Request for activation of the working speed control enable via the body manufacturer CAN . The setting of the event "950D" with its freeze frame data takes place as in the case of the discrete request.
Parameterization possibilities:
Any signal from Any signal from
body manufacturer CAN Use signal from the body
manufacturer CAN.
Permanent LOW Function deactivated
(signal ID 1000)

Working speed control request from power take-off (PRO)
Request from PTO for activation of the working speed control enable.
Parameterization possibilities:
Request for For activation of
working speed control working speed control,
Function module "PTO" the request from the
(signal ID 10ED) "Power take-off" function is taken
into consideration.
Inquiry deactivated Querying of this condition
(signal ID 300B) is deactivated

Brake
Activation input (bit signal) as condition for working speed control enable.
Parameterization possibilities:
Brake lights actuated Querying of the brake for
(signal ID 107F) activation of working speed control
Permanent LOW Querying of this condition
signal ID 1000) is deactivated

Hand brake

Querying of this condition cannot be deactivated.

Activation input (bit signal) as condition for working speed control enable.
Parameterization possibilities:
Hand brake applied Querying of the hand brake for
(signal ID 1055) activation of working speed control

Selector lever in position "N", with transmission 722.6

The availability of the signal depends on the vehicle equipment.

Activation input (bit signal) as condition for working speed control enable.
Parameterization possibilities:
Selector lever in position "N" Querying of the neutral position for
(signal ID 10F2) activation of working speed control
Inquiry deactivated Querying of this condition
(signal ID 300B) is deactivated

Engine at idle
Activation input (bit signal) as condition for working speed control enable.
Parameterization possibilities:
Engine at idle Querying of the engine idle for
(signal ID 113D) activation of working speed control
Inquiry deactivated Querying of this condition
(signal ID 300B) is deactivated

Clutch pedal depressed or fully depressed

The availability of the signal "Clutch pedal fully depressed" depends on the vehicle equipment.

Activation input (bit signal) as condition for working speed control enable.
Parameterization possibilities:
Clutch pedal depressed Query whether the clutch pedal
(signal ID 11C4) is depressed for activation of the
working speed control
Clutch pedal Query whether the clutch pedal
fully depressed for is fully depressed for
(signal ID 10F1) activation of working speed control
Inquiry deactivated Querying of this condition
(signal ID 300B) is deactivated

The transmission neutral position switch is fitted on vehicles with the following equipment:
- with code (MJ6) Engine start/stop system
- With code (E07) Starting-off aid
- with code (ZG1) Engageable all-wheel drive, with code (ZG2) Permanent all-wheel drive, with code (ZG3) Gear reduction for all-wheel drive or with code (ZG4) Permanent all-wheel drive with gear reduction

The clutch pedal switch for the inquiry "Clutch pedal fully depressed" is fitted on vehicles with code (MJ6) Engine start and stop system.

Freely parameterizable CAN signal
Activation input as condition for working speed control enable.
The procedure is as follows:
- Signal = Any signal
- Type of signal = Bit or other signal
- Type of evaluation
- With bit signal = Signal inverted or non-inverted
- With other signals = Threshold and whether signal must be above or below threshold

Parameterization possibilities:
Any signal Any signal can be used here.
Inquiry deactivated Querying of this condition
(signal ID 300B) is deactivated.

Further parameters for freely parameterizable CAN signal "working speed control"
These must be parameterized in the working speed control properties:
- Threshold (value range = 0 to 65 535)
- Threshold evaluation, selection = Value must be higher or lower than threshold
- Invert (with bit signals only), selection = Yes or no

Waiting time after "Clutch depressed"
For the time which is stored in the parameter working speed control clutch waiting time, the clutch status must be " clutch pedal depressed/fully depressed " (depending on the parameterization), in order to consider this condition as met in the function module working speed control.
If the parameter "Waiting time after "Clutch depressed"" is set to 0, checking of the clutch status is deactivated in the function module "Working speed control".

Waiting time for function enable
After all other input conditions have been fulfilled, the time which is stored in the parameter "ADR function enable waiting time" must expire in order for this condition to be regarded as fulfilled in the function module "Working speed control".
If the parameter "ADR function enable waiting time" is set to 0,
checking of this waiting time is deactivated in the function module "Working speed control".
Further parameters for working speed control:
- Maximum motor speed
- Maximum torque
- Maximum speed

Parameters for "Change of motor speed" function
Request "Rpm increase" from discrete input, activation input (bit signal) for rpm increase in function module "Change of motor speed".
Parameterization possibilities:
Any signal Any signal can be used here.
Permanent LOW Function deactivated
(signal ID 1000)

Request for rpm increase from body manufacturer CAN
Activation input (bit signal) for rpm increase in function module "Change of motor speed".
Parameterization possibilities:
Any signal from Any signal from
body manufacturer CAN Use signal from the body
manufacturer CAN.
Permanent LOW Function deactivated
(signal ID 1000)

Request "Rpm reduction" from discrete input
Activation input (bit signal) for rpm reduction in function module "Change of motor speed".
Parameterization possibilities:
Any signal Any signal can be used here.
Permanent LOW Function deactivated
(signal ID 1000)

Request for rpm reduction from body manufacturer CAN
Activation input (bit signal) for rpm reduction in function module "Change of motor speed".
Parameterization possibilities:
Any signal from Any signal from
body manufacturer CAN Use signal from the body
manufacturer CAN.
Permanent LOW Function deactivated
(signal ID 1000)

Request "Rpm resumption" from discrete input
Activation input (bit signal) for rpm resumption in function module "Change of motor speed".
Parameterization possibilities:
Any signal Any signal can be used here.
Permanent LOW Function deactivated
(signal ID 1000)

Request for rpm resume from body manufacturer CAN
Activation input (bit signal) for rpm resumption in function module "Change of motor speed".
Parameterization possibilities:
Any signal from Any signal from
body manufacturer CAN Use signal from the body
manufacturer CAN.
Permanent LOW Function deactivated
(signal ID 1000)

Further parameters for changing motor speed
The following parameters are available for changing motor speed:
- Ramp slope (in ramp mode)
- Value range = 0 up to 255 rpm per second

- Jump height (in stage mode)
- Value range = 0 to 255 rpm

- Switchover time from stage to ramp mode
- Value range = 0 to 25.5 s, in 100 ms steps

Parameters for "Rpm limitation" function

Request "Maximum rpm 1" from discrete input
Activation input (bit signal) for selection of maximum rpm limit 1.
Triggers output of the parameter "Maximum rpm 1" or output of limit set 1 (in the case of parameterization of the function "Output of limits without working speed control") at the output of the function module "Rpm limitation".

Limit set 1 consists of the following parameters:
- Maximum rpm 1 (rpm limitation without working speed control)
- Maximum vehicle speed 1 (rpm limitation without working speed control)
- Maximum torque 1 (rpm limitation without working speed control)

Parameterization possibilities:
Any signal Any signal can be used here.
Permanent LOW Function deactivated
(signal ID 1000)