COMM SET and PARITY

[Aslan Babakhanov]

I'm programming big led displays with rs232 connectivity and faced with parity problem.
It seems that combination
COMM SET #hComm, PARITY = %TRUE
COMM SET #hComm, PARITYTYPE = 3
doesn't work with v9.0.
Tested with Serial data logger programms and got paritytype = 0, since other programms can set up paritytype > 0.

Can someone be able to run simple test with rs232 devices to check whether the paritytype can be >0 ?

Many thanks,
Aslan.

[Cliff Nichols]

Aslan,
Got a sample? I work with Serial Port all the time, so this would be a new one to me???

[Dale Yarker]

Aslan,

What are the BYTE and STOP settings?

If you set BYTE = 8, STOP = 1 and PARITYTYPE = 3; the sent character would appear exactly the same as BYTE = 8, STOP = 2 and PARITYTYPE = 0.

Is there also a problem with PARITYTYPEs 1 and 2?

To me PARITYTYPEs 3 and 4 seem pretty useless unless you're padding BYTE = 7 at one end to look like BYTE = 8 at the other end.

Cheers,

[Aslan Babakhanov]

here is the code,

COMM OPEN "\\.\COM1" AS 1
IF ERRCLEAR THEN EXIT FUNCTION       ' Exit if port cannot be opened
COMM SET 1, BAUD     = 9600    ' 9600 baud
COMM SET 1, STOP     = 0         ' 1 stop bit
COMM SET 1, BYTE     = 8         ' 8 bits 
COMM SET 1, PARITY   = %TRUE ' tested even with PARITY = 1
COMM SET 1, PARITYTYPE = 3    ' MARK - setup first line
COMM SEND 1, CHR$(0,0,0,&h11,0,0,"ABCDEF")
COMM CLOSE 1

There are no return values from device, it receives only commands.

Parity 3 used in conjuction with Flow = NONE used to control first line on led
Parity 4 used in conjuction with Flow = Xon/Xoff used to control second line on led.

I've tested all possible combinations and no luck. The log file sais that pairty is 0....


Also, I couldn't setup following lines using internal PB commands:

        IOCTL_SERIAL_SET_HANDFLOW - Request sets the configuration of handshake flow control
            ControlHandShake - 0x1 (SERIAL_DTR_CONTROL)
            FlowReplace - 0x40 (SERIAL_RTS_CONTROL)
            XonLimit - 512
            XoffLimit - 512

Log lines after running my prog.

           ControlHandShake - 0x1 (SERIAL_DTR_CONTROL)
           FlowReplace - 0x42 (SERIAL_AUTO_RECEIVE | SERIAL_RTS_CONTROL)
           XonLimit - 2048
           XoffLimit - 512

[Michael Mattias]

Wrong OPEN syntax for COM1? My help file (8.03, version in use not shown) says of COMM OPEN..

Restrictions ..... When opening ports above COM9, Windows requires the port name to be specified using the following syntax:

COMM OPEN "\\.\COM15" AS #hComm

The underline of "above" [COM9] is in the help file.

(Not that what Windows wants should mean anything. COMM OPEN is a PowerBASIC function... what should matter is what PowerBASIC wants!)

(COMM is not one of my areas of competence. This is just an idea.)

[Aslan Babakhanov]

All,

Thanks for your suggestions.
I got correct com connection/transfer by playing with different settings.

These commands

COMM SET #nComm, STOP = 0
COMM SET #ncomm, BYTE = 8
COMM SET #ncomm, DTRLINE = %TRUE ' SERIAL_DTR_CONTROL
COMM SET #ncomm, RTSFLOW = 1 ' SERIAL_RTS_CONTROL
COMM SET #nComm, PARITY = %TRUE
COMM SET #nComm, PARITYTYPE = 3
COMM SET #nComm, PARITYCHAR = 0
COMM SET #nComm, PARITYREPL = %FALSE

performs the operations below:
ControlHandShake - 0x1 (SERIAL_DTR_CONTROL)
FlowReplace - 0x40 (SERIAL_RTS_CONTROL)

with parity enabled.

Aslan.