Overview of functions - Version 1.1

Table of contents

This document provides an overview of the most important functions of the control unit. It does not
deal with programming and individual configuration or the resulting boundary conditions!

The PSM (Parametrisable Special Module) control unit forms the interface between the vehicle and the body manufacturer.
Functions specific to the body manufacturer (e.g. working engine speed control) that are not implemented in other control units are implemented in the PSM.
The PSM has 10 inputs and 20 outputs that can also be used as inputs.
Complex bodies that require more inputs / outputs should be connected to the PSM via the BM CAN.

The current hardware and software status is important so that the functions of the PSM can be used in full! (From HW: 0523 and SW: 0545, the full scope is available!)
The engine control unit (ECU) must be released / coded accordingly and the VAS (5051/2)tester should have a version V10.x or newer (VAS 5063 from version 6.130 or newer!)

The signals are managed in a signal pool in the PSM. A signal may also be dependent on other signals, e.g. terminal15.
Currently, the I-CAN, the discrete inputs and outputs, the internal function units and the body manufacturer CAN are used as sources or outputs.

In total, 10 inputs are available:

• 3x high active
• 3x low active
• 4x analog (can also be set as digital inputs in the parameters) 

Inputs 1, 2 and 3 (high active)
(Switch to terminal 30, terminal 15)

• Int. pulldown resistor when control unit active!
• Individual wake-up function can be set in the parameters
• Status is stored in the signal pool

Inputs 4, 5 and 6 (low active)
(Switch to terminal 31)

• Int. pullup resistor, can be set individually in the parameters
• Individual wake-up function can be set in the parameters
• Status is stored in the signal pool

Inputs 7, 8, 9 and 10 (analog)
(Switch to terminal 30, terminal 15 or terminal 31)

• Int. pullup resistor (100 k, 1.2 kohm)
• Wake-up function for 7 and 8 can be jointly set in the parameters
• Digital value or analog value is stored in the signal pool

Parameter setting option: Input as switch or button  

In total, there are 20 outputs available:
The individual outputs can be outputs switching to terminal 30 (+12 V) or earth.

• 4x high side 500 mA
• 4x low side 500 mA
• 2x high side 1 A
• 2x low side 1 A
• 4x high side 5 A
• 2x half-bridge 5 A
• 1x high side 10 A

The following applies in general to the outputs:

• Short-circuit detection
• Statuses of the outputs are stored in the signal pool
• On high-side outputs, the load is applied by the PSM with terminal 30, i.e. the earth must be connected to the body earth or battery earth.

Options that can be set in the parameters:

• Dependency on vehicle status
• Use as output or input

Output 1 and 2 (half-bridge 5 A)

• Use as low side or high side
• Open load detection
  (Application: e.g. for motor right/left running)

Output 3, 4 and 5, 6 (high side 10 A and 5 A)

• Options that can be set in the parameters: Internal pullup, wake-up function, open load detection
  (Application: e.g. for switching on external consumers, 12 V socket)

Output 7 and 8 (high side 5 A)

• Options that can be set in the parameters: Internal pullup, open load detection(Application: e.g. for switching on external consumers)

Output 9 and 10 (high side 1 A)

• Options that can be set in the parameters: Internal pullup, open load detection, softstart
• Use as PWM output (500 mA)

(Application: e.g. as control signal for external components, switches to terminal 30)

Output 11 and 12 (LOW side 1 A)

• Options that can be set in the parameters: Open load detection

(Application: e.g. as control signal for external components, switches to earth)

Output 13, 14, 15 and 16 (high side 0.5 A)

(Application: e.g. as control signal for external components, switches to terminal 30)

Output 17, 18, 19 and 20 (low side 0.5 A)

(Application: e.g. as control signal for external components, switches to earth)

Options that can be set in the parameters for the outputs

• Open load detection (only A01-A12)
• Short-circuit monitoring
• Wake-up function (only A03, A04, A05 and A06)
• Input / output (all outputs can also be set in the parameters as inputs)
• PWM softstart
• PWM output (switch or PWM output)
• High side / low side (half-bridge A01 and A02)
• ICAN error
• PSM global undervoltage
• Terminal 61 (output is only active when terminal 61 ON)
• Terminal 15 (output is only active when terminal 15 ON)
• Terminal 15R (output is only active when terminal 15R ON)
• Terminal 15C (output is only active when terminal 15C ON)
• ZV open
• PSM run-on (global run-on or lifeguarding function can be set in the parameters) 

• Global PSM run-on time (ensure after ZV closed via external)
• Global PSM undervoltage, thresholds (100 mV) and response time (100 ms) (only for discrete and PLC outputs, functional undervoltage and overvoltage detection is not cancelled).
• Current switch-off thresholds on outputs with wake-up functions set in the parameters (output 3, 4, 5 and 6)

Each signal has a unique identification in the form of a signal number.
The signals are used by setting the parameters of the individual functions.

• Bit information (e.g. terminal 15, signal ID 1018)
• 1-byte information (e.g. vehicle speed, signal ID 2014)
• 2-byte information (e.g. engine speed, signal ID 3001)
• Multi-byte information as pointer (e.g. VIN, signal ID 4000)

• I-CAN
• BM CAN
• Discrete inputs
• PSM to I-CAN
• Internal signals
• A/D converter

I-CAN
The interior CAN is the vehicle CAN bus system by means of which the comfort control units communicate with one another.

BM CAN
The body manufacturer CAN (BM CAN) serves as the communications basis for BM control units.

RS-485 SOFA bus
The PSM has a serial interface to other control units such as taxameter, card reader…Baud rate : 19600 bit/s, Data direction : Bi-directional, half-duplex mode Master : PSM Voltage : 5V

The following vehicle functions can be controlled via the PSM.

• Vehicle status (terminal 15, terminal 61, ZV…)
• Lamp status (LDS and LSS requirements)
• Window status (windows wiping / heating)
• Central locking
• Alarm functions (alarm flashing, warning flashing….)
• Lamp control (parking lamps, marker lamps…)
• Sliding roof
• Various functions (buzzer in combi, charging active …)
• Combi warning signals (PSM defective, PSM undervoltage…)

Refer to the signal list for a detailed presentation. 

Parameter setting options of the vehicle functions

• Alarm flashing (priority and wake-up function)
• Steering angle reset (the function of the indicator reset by the steering angle can be switched on with this bit for the indicator outputs)
• Switch / button evaluation

Parameter setting of undervoltage detection

The undervoltage detection that can be set in the parameters (thresholds and times are in LID $33) makes it possible to make functions of the control unit independent from the vehicle electrical system voltage. This undervoltage detection does not revoke the function of hardware undervoltage detection in the control unit; instead, it should be viewed as a configurable supplement to this function.
The evaluation of the vehicle electrical system voltage is always performed on the larger of the two terminal 30 connections of the control unit. This means the function of undervoltage detection is ensured even if a connection fails.
The following signals are generated:

Run-on time can be set in the parameters
The PSM variables parameter set (LID $33) contains the "global PSM run-on time" variable. It contains the adjustable run-on time of the control unit. This time is specified in minutes.
The run-on time expires when "ZV open" is reset. The run-on time is re-initialised when "ZV open" is set and reset. After the run-on time set in the parameters has expired, the control unit can enter SLEEP mode if it is not kept active by other conditions, e.g.: individual discrete outputs are active.
During the run-on time, all functions of the control unit can still be operated providing they do not require information from the I-CAN.

Internal lifeguarding functions in PSM that can be set in the parameters
The PSM can be kept active by the application / parameter settings using this function module. This means it is possible to prevent the PSM going into SLEEP mode even though all the internal conditions necessary have been met. This possibility is important for functions that require the PSM to remain active throughout and for which the time restrictions of the normal PSM run-on are not sufficient.

Important: If using correctly, the PSM cannot enter SLEEP mode and this results in increased idle current consumption!

In order to activate the function, it is necessary to set the "PSM lifeguarding active" 0x01 in parameter set PSM variables (LID $33).
Following this, the function can be switched on using any bit signal from the signal pool (e.g. PLC output, discrete input, etc.).

The PSM offers the possibility of influencing the engine control unit externally. Several function modules with variable parameters have been implemented for this purpose to ensure correct operation of the engine control unit. 

The working engine speed control function enables the actual engine speed of the engine to be controlled.
It is possible to specify 3 set engine speeds that can be activated using a switch or rocker.
In addition, it is possible to use a hand-operated accelerator to set the engine speed, as well as with the accelerator pedal or the BM CAN bus.
ADR ensures that the minimum and maximum engine speeds set in the parameters cannot be exceeded. Torque limits and speed limits can be set in the parameters.
Working engine speed control enables the body manufacturer to influence the engine speed.

ADR requires the following input conditions for internal function enable:

• ADR module activated (parameter)
• Engine speed output permitted (parameter)
• Terminal 15 active + normal voltage
• Gearbox in neutral (output)
• Engine idling (output)
• Parking brake applied (output)
• Brake applied (output)
• Speed not too high (parameter)
• Clutch disengaged (output) 
• Any I-CAN signal active (output + parameter)
• Function enable time expired (output + parameter)

If these conditions are met, internal function enable can be activated using output "ADR request discrete" or BM.
Some of these conditions can be deactivated in the parameter settings.
If the conditions are not met, event 950D is stored in the error memory. The missing conditions are
stored in the environment data.

Any I-CAN signal

• Any signal from the signal pool
• Can process bit information or an analog value
• Processing type can be configured

Engine speed variation (DZA)
Function module for engine speed variation

Pulse and ramp mode (PUR)
Function module for ramp mode
This operating mode has the lowest priority and can only be activated if neither a set engine speed or the hand-operated accelerator are active.
Ramp mode can be activated using a cruise control lever, discrete inputs on the PSM or the BM CAN.

Engine speed limit (DZB)
Function module for engine speed limiting

Set engine speed selection (FDZ)
Function module for specifying the set engine speed

Set engine speed and limiting enable (FDZB)
Function module for enabling the set engine speed and limiting
Up to 3 different engine speeds can be set in the parameters.

Power take-off (PTO)
The power take-off function controls activation of the power take-off.

Speed limiting (VBEG)
Speed limiting makes it possible to switch on a speed limit set in the parameters.

Remote engine start and stop
The engine start / stop function enables the engine to be started and stopped by the PSM.
(Only in conjunction with ADR) 

BM CAN

• CAN class C
• Baud rate can be set in the parameters 125/250 kbaud
• Extended identifier 29-bit
• Tranceiver Error tolerant (TJA 1041)
• Terminating resistor 120 ohm
• Nominal voltage 5V
• Standard software driver
• Application can be set in the parameters No BM CAN / FMS / ISO11992 / auxiliary
• 4 user-definable messages

All bus content can be separated by the parameter settings and activated independently:

• FMS (only send direction)
• ISO11992-2 and 3 (excerpts)
• User-definable messages (J1939)

FMS
The fleet management system (FMS) only contains messages to be sent by PSM.
The content includes vehicle information (speed, engine values and driver information).
Engine values: Engine speed, oil temperature or water temperature
Driver information: Check lamps, warning messages
WIV data is currently not held in the data pool.

ISO11992-2
This standard contains send and receive messages. The send messages contain similar information
as the FMS, with the addition of some engine information. The signals received by PSM are stored in
the signal pool and can be used by ADR, for example.

User-definable messages

• 4 messages in send direction (GPM_1H,GPM_1I,GPM_1J, GPM_1K)
• 4 messages in receive direction (GPM_2H, GPM_2I, GPM_2J, GPM_2K)
• Send signals are sent from the signal pool (outputs)
• Receive signals are stored in the signal pool
• Cycle times of the messages 2x with 100 ms, 1x with 500 ms, 1x with 1000 ms
• Structure of the messages:
  8 bit signals
  2 byte signals
  2 2-byte signals

BM CAN signal list / see appendix for description!

PLC functions are provided in PSM for the LT3/Crafter. These functions should enable the customer to
implement straightforward logical operations between signals in the PSM signal pool.
It should be possible to set the parameters of the PLC functions, i.e. the customer has a free choice of
the origin of the PLC functions' input signals. The parameters are set via the diagnostic interface.

In addition, it is possible to set parameters such as thresholds and times for some block.

The following logical blocks are provided:

16 AND/OR/EXOR/NOR/NAND/EXNOR operation
8 RS and D flipflops
4 re-triggerable / non re-triggerable timers
4 threshold value switches with 4 stages
4 hysteresis elements with adjustable hysteresis thresholds
4 counter blocks

Activation of PLC groups
Processing of each of the total 4 groups can be activated or blocked by the module activation PLC
parameter set, irrespective of the other groups.

Block with logical operations
A logical block has 4 digital inputs and 2 digital outputs, in which case the 2nd output is always the
inversion of the 1st.

Timer block
The timer block has a digital trigger input and 2 digital outputs, in which case the 2nd output is always the inversion of the 1st output.

Counter block
The counter block is an element for counting edge changes. When the positive edges are counted!

Flipflop block
The flipflop block has a digital input (reset/clock), an analog input (set/data), an analog output A and a digital output B, in which case the digital output is always the inversion of the analog output.

Threshold value switch
The threshold value switch has an analog input that can process a signal with max. 16-bit width, as well as 3 digital outputs. The input value is compared with up 4 threshold values and the corresponding output is then set.

For this block to function correctly, make sure that the values set in the parameters for the thresholds comply with the following condition:
Threshold A < threshold B < threshold C < threshold D

The parameters of the inputs of the block are set in the same way as the parameters for the ADR function blocks for the discrete outputs.

Hysteresis block
The threshold value switch has an analog input that can process a signal with max. 16-bit width, as well as 2 digital outputs, in which case the 2nd output is the inversion of the 1st output.
This block makes it possible to convert an analog signal with a Schmitt trigger into a digital signal. The switching thresholds can be set in the parameter settings.

The parameters of the inputs of the block are set in the same way as the parameters for the ADR function blocks for the discrete outputs.

Internal structure of the PLC blocks
Each of the 4 blocks contains 4 logic blocks, 1 timer block, 2 flipflop blocks, 1 threshold value switch and one hysteresis block

The system processes the groups in following sequence: First group 1, then group 2, group 3 and finally group 4. It takes about 200 μs computing time to process a group.

All groups are processed in a 20 ms time window, however. During this processing, no signals can be modified in the signal pool by external sources (I-CAN, discrete inputs, etc.), therefore ensuring that all PLC groups have the same input information.

At the end of processing of a PLC group, the outputs of the individual blocks of the group are put in the signal pool. This is important so that these results will be available for processing of the subsequent groups, and therefore in order achieve short cycle times.

IMPORTANT: Regular processing of the PLC groups in a 20 ms grid is no longer assured during active diagnosis and, in particular, during parameter settings!

Various presets are contained in the flash memory for setting the PSM. Each of the active outputs are
listed below. The outputs not listed here have their signals set with the OutPortAus signal.

When a parameter set is selected, the parameter settings of both the discrete outputs and the I-CAN
outputs are copied. The copying process is only performed on request in diagnostic mode.
If a parameter set is copied from the flash memory into the RAM, this will no longer be contained in the
RAM after a reset.

1 basis status 
2 input on output
3 lamps 1 (LDS)
4 lamps 2 (LSS)
5 alarm lamps (wake-up with CAN)
6 indicator lamps (without CAN wake-up)
7 LSS functions
8 ADR
9 ADR + PTO

The 9 presets set the parameters of a:

• I-CAN outputs
• Discrete outputs
• ADR and PTO functions
• PLC functions
• PSM variables
• Signal times
• ADR/PTO/VBEG/MSTART/MSTOP parameters
• PLC parameters
• BM CAN parameters

Version 1.0, 28.07.2006
Version 1.1, 01.08.2006 Precondition for use for ADR, remote engine start and stop

BM CAN signal list / description

 

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