Appendix (Serial Port Interface Protocol; A1 Introduction; Enabling The Serial Port; Connecting To The Serial Port - Nellcor NPB-190 Service Manual

APPENDIX (SERIAL PORT INTERFACE PROTOCOL)

A1 INTRODUCTION
A2

ENABLING THE SERIAL PORT

A3

CONNECTING TO THE SERIAL PORT

A1 Introduction

A2 Enabling the Serial Port
A3 Connecting to the Serial Port
A4 Real-Time Print Out
A5 Nurse call
When connected to the serial port on the back of the NPB-190, a real-time
printout can be obtained. Data lines are printed at 2 second intervals. Column
headings will be printed after every 25 lines, or if one of the values in the
column heading changes. Changing an alarm limit, for example, would cause a
new column heading to be printed. Printouts include patient and device data. A
real-time printout cannot be obtained if the unit is operating on battery power.
The real-time printout is discussed in more detail in Paragraph A4.
Real-time data is constantly being sent to the serial port of the NPB-190 when
the instrument is operating on AC power. To receive a real-time printout, see
Paragraph A3 for instructions to make the connection.
Menu Item 6 is used to change baud rate. Item 6 cannot be accessed when a
sensor cable is connected to the instrument. To access menu Item 6, press both
the Upper Alarm Limit and the Lower Alarm Limit buttons simultaneously for 3
seconds. Next, press the Upper Alarm Limit button until menu Item 6 is
displayed. The baud rate can then be selected by pressing the Adjust Up or
Adjust Down button until the desired baud rate is displayed. A baud rate of 9600
is selected as a default value. Other baud rates that can be selected are 2400 and
19200.
Data is transmitted in the RS-232 format. Only three lines are used; GND is the
ground, TxD represents the Transmit Data Line, and RxD is the Receive Data
Line. Data can be transmitted a maximum of 25 feet. The pin outs for the serial
port are listed in the chart below.
Pin
2
3
5,10
11
1, 4, 6-9, 12-15

Table A-1: Serial Port Pin Outs

Line
RxD
TxD
GND
Nurse call
No Connection
A-1