Fresenius Medical Care 4008 4/09.03 (TM) 8-237
8.29 P.C.B. LP 763 Multi interface board (COMMCO III)
8.29.1 Description
P.C.B. LP 763 is an interface board for the 4008 series. It is provided for communiction and data
exchange of the CPU1 with other components inside or outside the machine.
● Functional groups
The P.C.B. LP763 comprises six functional units:
– RS232 interface
– Keybox interface
– CAN interface
– COMMCO-1 interface
– BTM interface
– DIP switch array (4)
● RS232 interface description
The interface chip SCC2698 (IC1) has eight serial channels. To obtain an RS232 level for
transmission, each channel is connected across a RS232 level converter (MAX238 IC2, IC3).
Each serial channel is wired to its own 10-pin plug. The plug connectors can be used to adapt new
components or as monitoring connections.
If nothing is stated to the contrary, the transfer parameters are 9600Bd, 8 data bits, 1 stop bit, no
parity.
The channels are either already allocated or reserved:
Conn. Channel Use Special feature
X2 a Standard HDF scale Baud rate 1200 Bd
X3 b Standard HDF HDF pump
X4 c Test channel
X5 d Heparin pump
X6 e FINESSE interface decoupled
(CAMUS protocol) 2400/9600Bd
X7 f Blood pressure monitor BPM ( in 4008H)
X8 g Blood volume monitor BVM (in 4008H)
X9 h not used
The serial channel e among these channels is specially designed. It is decoupled and has a
dielectric strength of 4 kV. Decoupling is ensured by two specially designed level converters
(MAX250, IC8 and MAX251, IC9) in conjunction with the optocouplers (OC1, OC3) and the
transformer UT1. Channel e is provided for the connection of a FINESSE system or a service PC.