Chapter 8 - Using MS-DOS
8-22
PL-5910 Series User Manual
Functions
EXTCOM.SYS 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 ex-
pansion 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-5910 series
units use ATPH59 for control, normally EXTCOM.SYS should be set to not use
port 3.
