5 Hardware and Software Statuses, Spare Parts Lists
7.3 Functional Description of the ME402
7.3.5 The Main Controller and its Interfaces
The main controller board coordinates all processes inside the ME402. Its central component is a C167 microcontroller equipped with a number of peripheral functions. This assembly can be subdivided into the following functional blocks:
• controller core and graphics controller
• I2C bus and its associated circuitry (periphery)
• SPI bus
• CAN bus, RS232 and footswitch (SIP/SOP) interfaces
• one-wire bus (as from HW02)
This module is located on the main board, directly behind the front panel.
7.3.5.1 Controller Core and Graphics Controller
The microcontroller used is a 16-bit system (C167) with integrated timer/counter functions and integrated A/D converter. Its configuration includes a non-multiplexed, 15-bit-wide address bus (LSB A0 not used) with four additional port signals as addresses A16 to A19, plus a 16-bit-wide data bus. An I2C bus master, a CAN controller and a RS232 transceiver (UART) are inte-grated as well.
Its immediate environment includes an external flash EEPROM as program memory, a static RAM and an external watchdog. In HW00 and HW01 units, the main controller board version I (C40-1926) has a program memory of only 1 MB; this has been increased to 2 MB in units with HW02 or higher hardware status. Upgrading the C40-1926 to 2 MB is basically possible, but requires returning either the board or the entire HF unit to the manufacturer. However, such memory extension is an absolute requirement for running SW2.368 or higher software ver-sions.
The controller allows you to reprogram the EEPROM via the serial interface. The boot program required for this task is executed in registers inside the controller. Therefore, software updates can be carried out very easily from outside – no need to open the unit. For HW00 and HW01 units, this involves setting the unit to boot mode via the Service menu. From HW02, this is no longer necessary, as the controller board version II (C40-2217) offers all the hardware fea-tures required.
To reduce the workload for the main controller, a separate graphics controller has been inte-grated that manages the screen contents and generates all signals needed for LCD screen con-trol. The generated image has a resolution of 640 x 480 color pixels; each color can be dis-played with a resolution of 6 bits. However, this function is used only for representing gray shades, as the color impression is more or less independent from the viewing angle for the full colors red, green and blue, the mixed full colors yellow, magenta and cyan, and white and black.
Units with hardware statuses HW00 to HW03 – with main controller boards I (C40-1926) and II (C40-2217) – have a graphics controller with integrated video RAM. Due to discontinuation of this component by the manufacturer, the main controller board III uses a graphics controller with external video RAM whose resolution of the colors red and blue is only 5 bits. However, this is of no significance for the specific application. A much more important difference be-tween versions I and II on the one hand and version III on the other hand relates to the con-verter used for operating the fluorescent tubes (screen backlight) – this concon-verter has been transferred from the controller board to the front board.
In HW00 to HW03 units, the LCD screen is connected to the graphics controller via a 34-pole ribbon cable. From HW04, a 31-pole, flexible flat connector is used for this purpose. This cable supplies the screen not only with power, but with all the signals required for its operation as well.
CR2032 lithium battery from HW02 BS\ WDI+5VHeartbeat
main controller board
Whereas the main controller is powered with +5 V, the graphics controller and some other functional groups operate on a voltage of +3.3 V. The two microelectronics operating voltages are generated from the voltage of +15 V by two switching controllers.
RAM A1-A17
CS1\ CS2\ CS3\
A1-A19
A1-A19
address bus
CS0\ CS4\
WRL\
VRAM (to clock) +5V
RSO\
WRL\
CSG\
CS4\CS0\
WRL\
WRL\
WRL\
RSO\CSG\
CR2032 Li ion battery
CPU config
BS\ WDI
+5VHeartbeat
main controller board from HW 04
(C40-2327)
+5V +15V+5VA
5VW X4.18c X5.23c
X4.13ac X5.14ac X4.28ac X5.16ac
X4.29ac X5.15ac
+15V +5V
X4.30ac X4.31ac
+5V
+15V
power manager board
main board
B1-B5
MA0-MA9 MD0-MD15 control
ICFL +15V
front board X1.8 X23.1X23.2 X23.3
front part
7.3.5.2 I2C Bus and Associated Bus Users
To enable control of a large number of peripheral indicators via LEDs – such as activation indi-cator, rotary switch backlight and NE status indicator – there is now a port expander available in the form of a serial synchronous data bus (I2C bus). These port expanders are connected to the main controller via a bidirectional data line and a clock line.
This bus also serves for connecting additional peripheral functions to the main controller. A serial EEPROM is provided for the non-volatile storage of user-defined as well as basic settings.
Besides, this bus is used for controlling the two external D/A converters that deliver the two analog signals TLS (for sound generator volume control) and PVW (for generating the
compari-+15V 7
main controller board
X4.20c X5.18a
power manager
board main board
+15V
front board
front part
X4.9 X4.10X1.9 X1.10 X4.15 X4.14
X1.15 X1.14
X4.16X1.16 X4.11X1.11 X4.12X1.12
X4.13X1.13 +5V
6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 +15V
+15V +5V
C40-2425-A activation indication
C40-2425-B socket illumination
X10.1
X7.1
1 2 1 2
2 3 4 5 6 7 8 9 10
B1 coag B2 coag
+15V
2 3 4 5
COAG +15V
C40-2423 rotary switch
backlight
X11.1
X8.1 X8.2 X8.3 X8.4 X8.5
X7.2 X7.3 X7.4 X7.5 X7.6 X7.7 X7.8
2 3
NE alarmNE good+15V
X1.1
X9.3
+15V
C40-2425-C NE status indication
+15V +5VD +5V
N.C.
X5.6c 4 5
X9.4 1WB1WB
HW04from
X9.5
However, an exhausted battery is of no consequence for the usability of the ME402 because the calendar clock, as well as the volatile parallel RAM, is intended only for service purposes such as saving error and activation logs. User-defined settings, in contrast, are stored in the non-volatile serial EEPROM, which needs no battery.
7.3.5.3 SPI Bus
Communication with internal functional groups on the controller module, as well as with the external functional groups “monopolar patient controller” and “Argon Beamer”, is ensured by a serial interface consisting of three bus lines for data transfer from the main controller (MOSI), data transfer to the main controller (MISO) and clock synchronization (CLK), plus an address line for each bus user. Connection to the monopolar patient circuit controller is established via
optocouplers, while connection to the external Argon Beamer is made through a main board driver linked to the connecting socket for the Argon Beamer.
The main controller board features two SPI bus users: The pulse pattern generator provides the signals used for controlling the HF generator; the sound generator generates the acoustic signals that indicate HF power activation, button operation (clicks) or alarm.
main controller board C40-1926, C40-2217 monopolar board
X6.2a -CSM X6.6a -CLK X6.5a +CLK
CSM- X7.7a CLK- X7.5a CLK+ X7.6a
X7.29c X7.30cX7.31c
X7.28cCSMO bipolar board
+15V
pulse pattern generator
MIST
GT1 GT2
IN MOSP MISP
TONTON X5.5a X5.5c X5.4c X5.4a
+12V MOSI
MISO
CSM
X5.13a X5.13c LSP1 X5.32a LSP2 X5.32c to HF
generator X8.2 X8.1
X5.25c X5.24a X5.24c X5.25a X2.2 MOSA X2.3 MISA
X21.3 GND X4.23a X4.21a TON
X5.17c
main board
argon beamer socket
(view from outside) MIST MISP CSMO
Two driving signals, GT1 and GT2, are required for driving the HF generator’s transistor bridge.
These involve pulse patterns that are specific for each type of current. The patterns are gener-ated by a programmable logic device (CPLD) but are set/provided by the main controller. In this process, the main controller charges the internal registers of this generator via the SPI bus. The internal signal GTEN enables the controller to switch the pulse pattern generator on and off.
Similar to the HF generator’s driving signals, the sounds for the acoustic indication of HF acti-vation and alarm statuses are also generated by a CPLD whose registers can be controlled by
These voices can be switched on or off by the controller via the internal signal TEN, either indi-vidually or collectively. Irrespective of this, the first voice can be switched on by the external signal TON that is derived from the HF generator’s driver stage. This ensures that an acoustic signal is present also during unintended activation of the HF generator.
A small audio amplifier drives the loudspeaker located on the unit’s rear panel. It allows vo-lume adjustment across a range of 45 dB to 65dB through the analog direct-voltage signal TLS. The corresponding setting can be made on-screen via a submenu.
main controller
X7.28cCSMO bipolar board
+15V
TONTON X5.5a X5.5c X5.4c X5.4a
+12V
X21.3 GND X4.23a X4.21a TON
X5.17c
main board
argon beamer socket (view from outside)
The main controller board III (C40-2327), implemented with HW04, involves a change in the internal address system for the SPI bus users, designed to increase the number of users that can be addressed. The software takes these differences into account by querying the hardware configuration. If an error occurs in this process and the hardware configuration is not identified correctly, this may lead to incorrect addressing of the SPI bus users, resulting in an error mes-sage such as “Patient circuit controller does not respond” or “CPLD xxx does not respond” or similar.
7.3.5.4 CAN Bus, RS232 and Footswitch (SIP/SOP) Interfaces
With the exception of the Argon Beamer connector, all external signal lines entering the unit are electrically isolated via optocouplers. This concerns the two serial interface sockets for CAN bus and RS232 and the two footswitch connecting sockets (used for large footswitch and small footswitch).
The CAN bus interface is a male DSUB9 socket for integration of the ME402 into an integrated OR system and for controlling an external smoke evacuator. The pin assignment complies with the SIOS industry standard. The CAN bus has an internal bus termination. If external bus ter-mination is required, the jumper X11 must be moved from 1-2 to 2-3.
main controller board
APOS
X9.1 CUT2 X8.3 CUT1 X8.2 COGB X8.1 APOS
main board
X9.3 APOS X10.20 BNEG X10.18 DTR X10.16 RXD X10.15 RTS X10.14 TXD X10.8 CPOS X10.5 BNEG X10.3 CANL
+5V
FCG1 FCG2 +5VB
CAN bus termination
+15V X5.14ac+15VX5.16ac
connector for RS 232 (view from outside)
COGB COG1
COG2
The RS232 interface is a female DSUB9 socket exclusively used for servicing the unit, e.g. for updating the software by download from a PC. Besides, it can be used for transferring all user settings to another unit, e.g. to a temporary replacement unit in the event that the regular unit must be repaired.
The large (dual-pedal) footswitch must be connected to the larger of the two footswitch sock-ets. The two pedal activation signals are received by optocouplers on the intermediate circuit side and then passed on to the controller as signals FCT1 and FCG1. In HW00 to HW03 units with main controller boards I (C40-1926) and II (C40-2327), the jumper X500 can be used to configure the input so that it can also be used for connecting an Erbe footswitch (for HF units of the ACC/ICC series) whose connector is basically identical to the KLS Martin plug but differ-ent in terms of pin assignmdiffer-ent. In units with HW04 or higher – with a controller board III (C40-2327) – the jumper array X3 not only allows operation of the Erbe ICC footswitch, but also supports the large footswitch with three contacts (basic setting) and enables connection of a small footswitch with two pedals. Besides, a footswitch interface circuit can be connected as well, e.g. for telemetric footswitch activation with power supply from the socket.
The small single-pedal footswitch must be connected to the smaller of the two footswitch sock-ets. It generates the controller input signal FCG2. However, this socket can also be used for connecting the small bipolar dual-pedal footswitch of the ME411 HF unit. In this case, the blue pedal corresponds to the black pedal of the single-pedal footswitch. In HW00 to HW03 units, the signal of the yellow pedal is supplied as FCT2 signal to the controller as well, but is cur-rently not used by the software. From HW04, this signal is supplied to the jumper array X3, from where it can also be assigned to the FCT2 signal.
To supply the line drivers of the serial interfaces and the optocouplers with voltage isolated from the intermediate circuit, the controller module features a small resonance converter that powers the interfaces via the T1 transformer.
7.3.5.5 One-Wire Bus
As from hardware version 02 and software version 1.336, the controller routinely checks the version statuses of the various boards. Therefore, from hardware version HW02 onwards, all boards feature a small memory with a one-wire bus interface, used for storing the respective ID data. This is necessary because the hardware version HW02 introduces new board versions with partially different properties. As these are used along with the boards already in use, the operating program must be capable of differentiating between the different types of board.
front part
X4.17
X1.1
C40-2425-2x NE status indication
hardware identifier C40-2425-C (from HW 04 only)
hardware identifier C40-2327
X5.6a
X5.7a
hardware identifier C40-2155 hardware identifier
C40-2281
bipolar board monopolar
board (from HW 03)
hardware identifier C40-2337
hardware identifier C40-2346
power manager board
X7.26c X27.1 X27.3 X27.5 X4.23c
controllermain board
hardware identifier C40-2471
front board
(from HW 04) X1.17
X1.2 X1.3 X1.4 X1.5
NE alarm
+15VX8.1 X8.2 X8.3 X8.4 X8.5
X6.1 X6.2 X6.3
boardmain