Pro-face PL-5900 Series, User Manual

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Chapter 6 - Setting Up Your PL OS
6-12
PL-5900 Series User Manual
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Description of Features
EXTCOM.SYS has the following features and uses a software interrupt (INT 14h)
to call the following functions.
INT 14h Function Code Chart
Function Code Explanation
00h Initialize Transmission port
01h Send 1 byte data
02h Receive 1 byte data
03h Read Transmission port status
10h Expansion setting
11h Forced 1 byte data send
12h 1 byte data reception (immediate reply)
13h Read Expansion Transmission port Status
15h Receive 1 byte data safely
16h Enable RS-485 Sending/Transmission
17h Disable RS-485 Sending/Transmission
FEh Resident Check
• RS-232C (COM1,COM2) and RS-485 (COM3) can be used even if the
EXTCOM.SYS program is not installed. However, the receive interrupt and expan-
sion features cannot be used.
• Depending on the BIOS function call used, the RS-232C (COM1, COM2) and RS-
485 (COM3) are enabled. Also, the RS-232C (COM1, COM2) can be used with only
a device name.
• Port 3 (COM4) can be used to control the Touch Panel. Since PL-5900 series units
use PLATPH for control, normally EXTCOM.EXE should be set to not use port 3.