The TNC-PI has the ability to return trash from PITNC-get if it is receiving data from a radio. I don’t know if this is what is happening for you but it seems to have better dialogs with the PITNC programs if the radio receiver is disconnected.
One way to know that PITNC-get is showing you garbage, is to look at the returned I2C address register, register #7. If it doesn’t match what you know the I2C address is, then you are getting garbage.
Sending a reset to the TNC, PITNC-set 0 0 register 15, data 2, will clear out all that, but if you are hooked to an active receiver, it’ll get garbage again, sometimes. I’m not clear on what the mechanism there, just that’s what it looks like to me.
The TXdelay can be written in the registers, like you are doing, but setting it via the Potentiometer seems to be more reliable. I don’t know why. You can program G8BPQ via the config to write a TXDELAY of 0 to the KIS parameters, I think. Then the potentiometer on the TNC-PI will have control of the TXDELAY.
This is what I use for a point to point dedicated link on our network.
Notice the TXDELAY=0 and the KISSOPTIONS.
PORTNUM=1 ; Optional but sets port number if stated
ID=p2p link to W1AW-4 ; Displayed by PORTS command
TYPE=I2C ; Port is RS232 Com or I2C Com
PROTOCOL=KISS ; TNC is used in KISS (or JKISS) mode
;;;;;;KISSOPTIONS=PITNC,NOPARAMS ;; don’t set NOPARAMS. we want params.
I2CBUS=1 ; 0 for Version 1 board, 1 for Version 2 board. Don't include this for RS232/USB TNCs
I2CDEVICE=6 ; Decimal I2C device-ID -- Don't include for RS232/USB TNCs
; ; See ..\RelatedFiles\KissRoms\KissRoms.zip.
FULLDUP=0 ; Only meaningful for KISS (or JKISS) devices
; IOADDR=1 ; 1 = SERIAL PORT COM1 ETC. << do not use if TYPE=I2C
SPEED=19200 ; RS232 COM PORT SPEED
CHANNEL=A ; A for single channel TNC, A or B for multichannel
PERSIST=225 ; PERSIST=256/(# of transmitters-1) — don’t set this to 255 else the two nodes can sync on failure
SLOTTIME=100 ; CMSA interval timer in milliseconds
TXDELAY=0 ; Transmit keyup delay in milliseconds 0 means leave it up to the TNC-PI
TXTAIL=1 ; TX key down, in milliseconds, at packet end
QUALITY=1 ; Quality factor applied to node broadcasts heard on
; ; this port, unless overridden by a locked route
; ; entry. Setting to 0 stops node broadcasts
MINQUAL=50 ; Entries in the nodes table with qualities greater or
; ; equal to MINQUAL will be sent on this port. A value
; ; of 0 sends everything.
MAXFRAME=1 ; # of frames that can be sent in a single transmission (1 thru 7)
FRACK=4000 ; Level 2 timout in milliseconds -- how long before we retry transmitting to neighbor
RESPTIME=30 ; Level 2 delayed ack timer in milliseconds -- how long after we receive from neighbor before we key up and acknowledge the transmission
RETRIES=20 ; Level 2 maximum retry value
PACLEN=236 ; Default max packet length for this port
UNPROTO=ID ; BT=EXT broadcast addrs format: DEST[,digi1[,digi2]]
; ; BCALL=KK4CFN-8 ; BTEXT call. unstated defaults to APPL1CALL
L3ONLY=0 ; 1=No user downlink connects on this port
DIGIFLAG=0 ; Digipeat: 0=OFF, 1=ALL, 255=UI Only
DIGIPORT=0 ; Port on which to send digi'd frames (0 = same port)
USERS=0 ; Maximum number of L2 sessions, 0 = no limit