Hello, I am trying to send/receive information via my serial port, and am having a strrange problem: I can read and write successfully via VBA only after es. We're getting closer.when I try to add MSCOMM to the form, I get: 'The control could not be created because it is not properly licensed' The help for. Serial port communication using MSComm control - posted in Ask for Help: Can someone please help me in implementing serial port communication using the MSComm control (MSCOMM32.OCX). Going through CoHelper.ahk I couldnt understand how to use the various methods provided by an interface.

Garritan Steinway Serial Number there. Hi, Nearly finished my virtual COM port but one outstanding issue - MsComm.ocx! Writing/IoCtl work fine; reading works fine under everything except Mscomm - read queue in driver is manual but whenever.Input method (aka read) is invoked on MsComm I get COM Exception 0x800A1F54 (under a.net app) or Run Time Error 8020 (under VB6 app) According to MS KB 318784 'MsComm does not expect the ReadFile method to return ERROR_IO_PENDING; strange, I'm completing the read request as fxRequest->CompleteWithInformation ( S_OK, bytesRead ) Any ideas as to what to do?

>According to MS KB 318784 'MsComm does not expect the ReadFile method = to return=20 >ERROR_IO_PENDING;=20 Correct. A well-known bug in MsComm.ocx. >strange, I'm completing the read request as = fxRequest->CompleteWithInformation Sorry, but KMDF has a queue above your code, which pends the IRP. Do all work in InCallerContext callback, or abandon KMDF at all, or live = with bug in MsComm.ocx (who on Earth uses this ancient stuff in 2010?) --=20 Maxim S. Krieghoff Model 32 Serial Numbers more.

Shatskih Windows DDK MVP xxxxx@storagecraft.com http://www.storagecraft.com. Maxim >According to MS KB 318784 'MsComm does not expect the ReadFile method to return >ERROR_IO_PENDING; Correct. A well-known bug in MsComm.ocx.

Been there, met it before, got around it in WDM:-)! >strange, I'm completing the read request as fxRequest->CompleteWithInformation Sorry, but KMDF has a queue above your code, which pends the IRP. Hmmm, I'm using UMDF Do all work in InCallerContext callback, or abandon KMDF at all, or live with bug in MsComm.ocx (who on Earth uses this ancient stuff in 2010?) Don't blame me, blame my client (who's still living in the past) More proper info - may help??? Write command which replies First read (of 1 byte) fails 8020, now 1 byte queued 2nd read (of 1 byte) fails 8020, now 0 bytes queued 3rd read (of 1 byte) doesn't fail and appears to read the Thanks Adrian. You don't have to abandon instead, but you do have to handle reads speciall= y so that mscomm32.ocx does not die. D sent from a phpne with no keynoard -----Original Message----- From: xxxxx@villasoft.co.uk Sent: May 31, 2010 10:29 AM To: Windows System Software Devs Interest List Subject: RE:[ntdev] Virtual COM Port driver / MSComm Maxim >According to MS KB 318784 'MsComm does not expect the ReadFile method to = return >ERROR_IO_PENDING; Correct.

A well-known bug in MsComm.ocx. Been there, met it before, got around it in WDM:-)! >strange, I'm completing the read request as fxRequest->CompleteWithInforma= tion Sorry, but KMDF has a queue above your code, which pends the IRP. Hmmm, I'm using UMDF Do all work in InCallerContext callback, or abandon KMDF at all, or live wi= th bug in MsComm.ocx (who on Earth uses this ancient stuff in 2010?) Don't blame me, blame my client (who's still living in the past) More proper info - may help???

Write command which replies First read (of 1 byte) fails 8020, now 1 byte queued 2nd read (of 1 byte) fails 8020, now 0 bytes queued 3rd read (of 1 byte) doesn't fail and appears to read the Thanks Adrian --- NTDEV is sponsored by OSR For our schedule of WDF, WDM, debugging and other seminars visit: To unsubscribe, visit the List Server section of OSR Online at sronline.com/page.cfm?name=3DListServer. I don't know the internals either. All i know is that if the ocx control ex= pects read data it will expect the read io request to complete synchronousl= y.