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Forum Index : Microcontroller and PC projects : OPEN syntax
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f2cf1g Newbie Joined: 18/11/2016 Location: United KingdomPosts: 13 |
Hi, newbie here with a problem. I want to open COM1 to accept an inverted signal so I've tried the following code: Dim STRING s Open "COM1:2400,,,,INV" As #1 Do s = Input$(1,#1) If s<>"" Then Print s; Loop I get an invalid syntax error on the OPEN statement which I can cure by filling in the missing parameters. The number fields are OK, I can just use the default values, but I also have to provide an interrupt routine address although I have no need for interrupts. I can't see how to proceed, no doubt it's something obvious, advice would be much appreciated. Roy |
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disco4now Guru Joined: 18/12/2014 Location: AustraliaPosts: 844 |
Hi Roy, I think INV is one off 5 special parameters that can be added without filling in missing parameters. so I think the following is OK OPEN "COM1:2400,INV" As #1 Regards Gerry From the 5.2 manual APPENDIX A All parameters except the serial port name (COMn:) are optional. If any one parameter is left out then all the following parameters must also be left out and the defaults will be used. Five options can be added to the end of 'comspec$' These are DE, 9BIT, INV, OC and S2: ‘DE’ will enable the Data output Enable (EN) signal for RS485. See the section "IEEE 485" for details. '9BIT' will specify that 9 bit transmit and receive is to be used. See the section "IEEE 485" for details. 'INV' specifies that the transmit and receive polarity is inverted (COM1: only). ‘OC’ will force the transmit pin (and DE on COM1:) to be open collector. This option can be used on both COM1: and COM2:. The default is normal (0 to 3.3V) output. 'S2' specifies that two stop bits will be sent following each character transmitted. (COM1: only) Latest F4 Latest H7 |
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f2cf1g Newbie Joined: 18/11/2016 Location: United KingdomPosts: 13 |
Thanks Gerry, you're right. Strange syntax. Roy |
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