Rs-232 Interface; Buzzer; Pcb Modem Supply Cs M; Internal Interfaces - GE MAC 1200 Servicing Instructions

GE Medical Systems MAC 1200 V 1.2 Page 19
Information Technologies 227 492 21 Rev F
2.3.11 RS-232 interface
The MAC1200 has an RS-232 interface accessible with a 9-pin Sub-D connector.
Except for the RS-232 driver chip, the interface is integrated into the control core of the
MPC821.
The interface has the following attributes:
m hardware handshake with the signals RTS and CTS
m or software handshake with XON/XOFF
m transmission speeds from 4800 ... 57600 Baud
m maximum input voltage range: +/- 15V
M minimum driver output voltage: +/- 5V
m maximum ESD interface protection: +/- 10kV
From version V1.1, MAC1200 additionally provides a modem power supply voltage and a
remote start input on the RS-232 interface.
2.3.12 Buzzer
The buzzer is an integrated signal generator with fixed frequency, directly operating from
the +5V logic power supply.
Activating and deactivating is controlled with the signal SPEAKER.
2.4 PCB Modem Supply CS_M
PCB Modem Supply CS_M generates a supply voltage of +8V dc, to operate a special GE
Medical Systems information Technologies modem direct on the RS-232 interface on the
MAC1200 without the need of an external power supply for the modem.
The Voltage is generated by a switching regulator with current limit and thermal protection
from the +26,5V (+UVERS).
The modem supply voltage +8V is accessible on Pin 6 of the RS232 interface.
The protection against ESD is realized with a Transzorb diode on the PCB Control CS CI.
2.5 Internal interfaces
2.5.1 Mechanical interfaces
Mechanical interfaces are described in Section "1.2 Mechanical Components.