AnsweredAssumed Answered

vrf Serial communications problem

Question asked by VRFuser on Apr 13, 2000
Hello Tom,

the error 701 is mostly fired when you want to read data from the serial
port but there is not enough in the queue.
Example: you expect an response of 10 bytes and therefore you give vee the
command to read an array of 10 bytes. By the time vee tries to execute this
command your device has only sended 8 bytes and the last are 'on the way'.
So vee gives error 701 directly without waiting for any timeout! And the
last two bytes are still in the input buffer. That seems to be a problem for
the SICL to reinitialize the com port again.
So the workaraound should be, to read your answer of the device byte by byte
and collect them in a collector object. Or wait long enough before you try
to read. Or use the DAV module in a loop and keep hold of the amount of
bytes in the buffer before reading it.

Does that help a bit?

        Georg Nied
   Software-Development
Hansestr.7 - 51149 Cologne
        Germany
Mail: gn-software@gmx.de


> -----Original Message-----
> From: owner-vrf@hplvlrx.lvld.hp.com
> [mailto:owner-vrf@hplvlrx.lvld.hp.com]On Behalf Of Mitchell,
> Tom (T.P.)
> Sent: Thursday, April 13, 2000 4:26 PM
> To: Vrf (E-mail)
> Subject: vrf Serial communications problem
>
>
> When I try to communicate to a device on the serial port, I
> get a couple of
> error codes returned occasionally.  I get a 811 and a 701.  I
> can recover
> and retransmit my data when I get a 811 code, but when I get
> a 701 error
> code, I cannot recover.  I need to exit Vee and run a different
> communications program on the port, then come back into Vee.
> Vee seams to
> have problems with serial communications.  I've tried
> resetting the port
> without any success.  Any ideas?
>
> Tom Mitchell
> Visteon Automotive Systems
> Software Validation/Product Assurance
> ETC Room B116
> 17000 Rotunda Drive
> Dearborn, MI 48121
> Voice/FAX number: (313) 323-9518    Text pager:(313) 795-2709
> EMAIL:tmitchel@visteon.com
> textpager 3137952709@alphapage.airtouch.com
>
>
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