Chapter 6 - Setting Up Your PL OS
PL-5900 Series User Manual
6-17
Function 15h
Receive 1 Byte Data Safely
Receives 1 byte data. However, the reception buffer is not refreshed. Also, re-
sponds immediately if the buffer contains no data.
Input:
AH = 16h
Output:
(None)
Function 16h
Enable RS485 Sending/Transmission
Receives 1 byte data. However, the reception buffer is not refreshed. Also, re-
sponds immediately if the buffer contains no data.
Input:
AH = 15h
AL = Transmission Data
DX = Port Number (0 to 3)
Output:
AH = Line Status
AL = Reception Data
Function 17h
Enable RS485 Sending/Transmission
Used with Multi-Drop connections, via the RS-485 port (No. 2).
When DTR turns OFF, transmission is not possible.
Input:
AH = 17h
Output:
(None)
Function FEh
Resident Check
When the EXTCOM.SYS program is resident, returns a fixed message and the
version (number).
Input:
AH = FEh
Output:
BL = "Y"
BH = "A"
CX = Version Number
Carry = Clear
