4-14 120 Series Maternal/Fetal Monitor Revision B
2015590-001
Theory of Operation: Main Motherboard
61 SP3B/ Output Spare Chip Select Line
62 +5V Output Volt Logic Supply
63 LDSB/ Output Processor Lower Data Strobe
64 R/WB/ Output Processor Read/Write Line
65 +15BP Output +15 Volt Supply for NBP Module
66 DTACK/ I/O Processor DTACK Transfer Line
67 RXDD Input Main Motherboard RXD Line from NBP Module
68 TXDD Output Main Motherboard TXD Line to NBP Module
69 CKE Output 20 MHz Clock
70 GND Output Digital Ground
71 No Connection — —
72 72kHz Output 72 kHz from US Board
73 RTSD Output Main Motherboard RTS Line to NBP Module
74 CTSD Input Main Motherboard CTS Line from NBP Module
75 GND Output Digital Ground
76 –15V Output Volt Analog Supply
77 AGND Output –15 Volt Analog Supply
78 +20I Output +20 Volts for Isolated Power Supply
79 +20I Output +20 Volts for Isolated Power Supply
80 RESA/ Output Processor Controlled Reset
Table 4-6. NBP Board Connector J4 (Continued)
Pin Number Signal Name Signal type Signal Description