Reading and writing from a serial port in C#, part 2
Question
I am trying to replace a C program with a C# one. The C program connects to an older computer via the COM1 serial port. I do not have any kind of information on how the C code connects to the other machine, but it does connect correctly, so I have to guess as to how it is doing it. I have been using Portmon to try to figure out how the C program is writing and reading successfully. I have also been running Portmon when my new C# application is running. In my C# program, I use the SerialPort class.
I am trying to determine what values the different items in the SerialPort class should have by using the output of Portmon on the working program. My thought is that if I can get the values correct for the class, it would write and read correctly. The program (below) is not working correctly. The program opens the COM1 port successfully, but it fails when it tries to write a period (and then another period). These give a timeout.
Looking at the output of Portmon running behind the old C program, the working program opened the COM1 port and then wrote one period and then another before reading a successful value (&OK) from the COM1 port. The old program set up several values that I want to duplicate in my C# program.
I have tried a variety of combinations of the SerialPort options below, but I obviously have not hit on anything.
BTW, I asked some preliminary questions in Stack Overflow question Reading and writing from a serial port in C#, part 2
I am using Windows XP on the machine that is running the programs. The machine on the other side of the COM1 port is a very old PC.
Is there a better way to do this? Use something other than Portmon? For the Portmon output for the old program the Process column is ntvdm.exe. Is that a problem? Should I not use the C# SerialPort class? Probably the most important question is: What values should I use for the Serialport class to match the old program?
My C# program:
SerialPort comport = new SerialPort();
comport.BaudRate = 9600;
comport.DataBits = 7;
comport.StopBits = StopBits.One;
comport.Parity = Parity.Odd;
comport.RtsEnable = true;
comport.DtrEnable = true;
comport.Handshake = Handshake.RequestToSend;
comport.ReadBufferSize = 8192;
comport.WriteBufferSize = 100;
comport.WriteTimeout = 30000; // 30 sec
comport.ReadTimeout = 30000; // 30 sec
comport.PortName = "COM1";
string tempFbuffer;
byte[] Fbuffer = new byte[200];
string alldata5;
tempFbuffer = "..";
for (int cnt = 0; cnt < tempFbuffer.Length; cnt++)
{
Fbuffer[cnt] = Convert.ToByte(tempFbuffer[cnt]);
}
comport.Open();
comport.Write(Fbuffer, 0, 1);
comport.Write(Fbuffer, 1, 1);
for (i = 0; i < 4; i++)
{
alldata5 = alldata5 + comport.ReadChar();
}
comport.Close();
The Portmon output of the application I want to mimic is below. This application connects to the other machine and works correctly. I manually put the headings in at the top.
As you can see, on lines 33 and 34 there are successful writes and then on lines 35 and 36, there are successful reads. I ran the program with Portmon in the background.
# Time Process Reuest Port Result Other
0 0.00004407 ntvdm.exe IRP_MJ_CREATE Serial0 SUCCESS Options: Open
1 0.00000198 ntvdm.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
2 0.00000115 ntvdm.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
3 0.00000104 ntvdm.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
4 0.00000106 ntvdm.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
5 0.0000008 ntvdm.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
6 0.00000082 ntvdm.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
7 0.00000085 ntvdm.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
8 0.00000081 ntvdm.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
9 0.00000712 ntvdm.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 1200
10 0.00000349 ntvdm.exe IOCTL_SERIAL_CLR_RTS Serial0 SUCCESS
11 0.00000366 ntvdm.exe IOCTL_SERIAL_CLR_DTR Serial0 SUCCESS
12 0.00000225 ntvdm.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: NONE WordLength: 5
13 0.00000111 ntvdm.exe IOCTL_SERIAL_SET_CHAR Serial0 SUCCESS EOF:0 ERR:0 BRK:0 EVT:0 XON:11 XOFF:13
14 0.00000735 ntvdm.exe IOCTL_SERIAL_SET_HANDFLOW Serial0 SUCCESS Shake:0 Replace:0 XonLimit:2048 XoffLimit:512
15 0.00000133 ntvdm.exe IOCTL_SERIAL_LSRMST_INSERT Serial0 SUCCESS Char: ffffffff
16 0.00000338 ntvdm.exe IOCTL_SERIAL_SET_QUEUE_SIZE Serial0 SUCCESS InSize: 8192 OutSize: 100
17 0.00000083 ntvdm.exe IOCTL_SERIAL_GET_TIMEOUTS Serial0 SUCCESS
18 0.00000092 ntvdm.exe IOCTL_SERIAL_SET_TIMEOUTS Serial0 SUCCESS RI:-1 RM:0 RC:0 WM:0 WC:0
19 0.00000349 ntvdm.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
20 0.00000342 ntvdm.exe IOCTL_SERIAL_SET_RTS Serial0 SUCCESS
21 0.00001121 ntvdm.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 1200
22 0.00000262 ntvdm.exe IOCTL_SERIAL_SET_WAIT_MASK Serial0 SUCCESS Mask: RXCHAR CTS DSR RLSD ERR RING
23 36.94054111 ntvdm.exe IOCTL_SERIAL_WAIT_ON_MASK Serial0 SUCCESS
24 0.00000403 ntvdm.exe IOCTL_SERIAL_CLR_DTR Serial0 SUCCESS
25 0.00000356 ntvdm.exe IOCTL_SERIAL_CLR_RTS Serial0 SUCCESS
26 0.00000351 ntvdm.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
27 0.00000348 ntvdm.exe IOCTL_SERIAL_SET_RTS Serial0 SUCCESS
28 0.00000717 ntvdm.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 9600
29 0.00000145 ntvdm.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
30 0.00000246 ntvdm.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: ODD WordLength: 5
31 0.00000086 ntvdm.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
32 0.00000226 ntvdm.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: ODD WordLength: 7
33 0.00002222 ntvdm.exe IRP_MJ_WRITE Serial0 SUCCESS Length 1: .
34 0.00002142 ntvdm.exe IRP_MJ_WRITE Serial0 SUCCESS Length 1: .
35 0.00000562 ntvdm.exe IRP_MJ_READ Serial0 SUCCESS Length 4: &OK.
36 0.00000239 ntvdm.exe IRP_MJ_READ Serial0 SUCCESS Length 0:
37 0.00000533 ntvdm.exe IOCTL_SERIAL_WAIT_ON_MASK Serial0 SUCCESS
38 0.0000023 ntvdm.exe IRP_MJ_READ Serial0 SUCCESS Length 0:
39 95.8854497 ntvdm.exe IOCTL_SERIAL_WAIT_ON_MASK Serial0 SUCCESS
40 0.00002486 ntvdm.exe IRP_MJ_WRITE Serial0 SUCCESS Length 1: D
The Portmon output of the C# application that I am creating is below. The C# code above, when run with Portmon in the background creates this output. I put in the headers.
As you can see, there is a timeout error on line 69 during the write. I need this to run close enough to the C one so that the writes and reads work.
Obviously the baud rate, wordlength, parity and several others are set correctly.
# Time Process Reuest Port Result Other
0 0.00004362 fancom.exe IRP_MJ_CREATE Serial0 SUCCESS Options: Open
1 0.0000019 fancom.exe IOCTL_SERIAL_GET_PROPERTIES Serial0 SUCCESS
2 0.00000263 fancom.exe IOCTL_SERIAL_GET_MODEMSTATUS Serial0 SUCCESS
3 0.00000096 fancom.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
4 0.00000097 fancom.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
5 0.00000084 fancom.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
6 0.00000097 fancom.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
7 0.00000081 fancom.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
8 0.00000088 fancom.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
9 0.0000008 fancom.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
10 0.00000079 fancom.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
11 0.00000715 fancom.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 9600
12 0.00000355 fancom.exe IOCTL_SERIAL_CLR_DTR Serial0 SUCCESS
13 0.0000024 fancom.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: ODD WordLength: 7
14 0.00000107 fancom.exe IOCTL_SERIAL_SET_CHAR Serial0 SUCCESS EOF:1a ERR:3f BRK:3f EVT:1a XON:11 XOFF:13
15 0.00000779 fancom.exe IOCTL_SERIAL_SET_HANDFLOW Serial0 SUCCESS Shake:8 Replace:84 XonLimit:1024 XoffLimit:1024
16 0.0000008 fancom.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
17 0.00000081 fancom.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
18 0.00000081 fancom.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
19 0.00000081 fancom.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
20 0.00000705 fancom.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 9600
21 0.00000349 fancom.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
22 0.0000022 fancom.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: ODD WordLength: 7
23 0.00000098 fancom.exe IOCTL_SERIAL_SET_CHAR Serial0 SUCCESS EOF:1a ERR:3f BRK:3f EVT:1a XON:11 XOFF:13
24 0.00000493 fancom.exe IOCTL_SERIAL_SET_HANDFLOW Serial0 SUCCESS Shake:9 Replace:84 XonLimit:1024 XoffLimit:1024
25 0.00000684 fancom.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
26 0.00000108 fancom.exe IOCTL_SERIAL_SET_TIMEOUTS Serial0 SUCCESS RI:-1 RM:-1 RC:30000 WM:0 WC:30000
27 0.00000227 fancom.exe IOCTL_SERIAL_SET_WAIT_MASK Serial0 SUCCESS Mask: RXCHAR RXFLAG CTS DSR RLSD BRK ERR RING
28 35.62327662 fancom.exe IOCTL_SERIAL_WAIT_ON_MASK Serial0 SUCCESS
29 0.00000399 fancom.exe IOCTL_SERIAL_SET_QUEUE_SIZE Serial0 SUCCESS InSize: 8192 OutSize: 100
30 30.00157726 fancom.exe IRP_MJ_WRITE Serial0 TIMEOUT Length 1: .
31 0.00000767 fancom.exe IRP_MJ_FLUSH_BUFFERS Serial0 SUCCESS
32 0.00001012 fancom.exe IOCTL_SERIAL_SET_WAIT_MASK Serial0 SUCCESS Mask:
33 0.00000402 fancom.exe IOCTL_SERIAL_CLR_DTR Serial0 SUCCESS
34 0.00000116 fancom.exe IRP_MJ_FLUSH_BUFFERS Serial0 SUCCESS
35 0.0000023 fancom.exe IOCTL_SERIAL_PURGE Serial0 SUCCESS Purge: RXABORT RXCLEAR
36 0.00000163 fancom.exe IOCTL_SERIAL_PURGE Serial0 SUCCESS Purge: TXABORT TXCLEAR
37 0.00000404 fancom.exe IRP_MJ_CLEANUP Serial0 SUCCESS
38 0.00322359 fancom.exe IRP_MJ_CLOSE Serial0 SUCCESS
39 0.00004607 fancom.exe IRP_MJ_CREATE Serial0 SUCCESS Options: Open
40 0.00000188 fancom.exe IOCTL_SERIAL_GET_PROPERTIES Serial0 SUCCESS
41 0.00000277 fancom.exe IOCTL_SERIAL_GET_MODEMSTATUS Serial0 SUCCESS
42 0.00000092 fancom.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
43 0.00000112 fancom.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
44 0.0000008 fancom.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
45 0.00000093 fancom.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
46 0.00000079 fancom.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
47 0.00000085 fancom.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
48 0.00000081 fancom.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
49 0.00000082 fancom.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
50 0.00000704 fancom.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 9600
51 0.00000352 fancom.exe IOCTL_SERIAL_CLR_DTR Serial0 SUCCESS
52 0.00000225 fancom.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: NONE WordLength: 8
53 0.00000113 fancom.exe IOCTL_SERIAL_SET_CHAR Serial0 SUCCESS EOF:1a ERR:0 BRK:0 EVT:1a XON:11 XOFF:13
54 0.00000489 fancom.exe IOCTL_SERIAL_SET_HANDFLOW Serial0 SUCCESS Shake:8 Replace:80 XonLimit:1024 XoffLimit:1024
55 0.00000084 fancom.exe IOCTL_SERIAL_GET_BAUD_RATE Serial0 SUCCESS
56 0.00000083 fancom.exe IOCTL_SERIAL_GET_LINE_CONTROL Serial0 SUCCESS
57 0.00000081 fancom.exe IOCTL_SERIAL_GET_CHARS Serial0 SUCCESS
58 0.00000081 fancom.exe IOCTL_SERIAL_GET_HANDFLOW Serial0 SUCCESS
59 0.00000696 fancom.exe IOCTL_SERIAL_SET_BAUD_RATE Serial0 SUCCESS Rate: 9600
60 0.00000344 fancom.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
61 0.00000222 fancom.exe IOCTL_SERIAL_SET_LINE_CONTROL Serial0 SUCCESS StopBits: 1 Parity: NONE WordLength: 8
62 0.00000102 fancom.exe IOCTL_SERIAL_SET_CHAR Serial0 SUCCESS EOF:1a ERR:0 BRK:0 EVT:1a XON:11 XOFF:13
63 0.00000474 fancom.exe IOCTL_SERIAL_SET_HANDFLOW Serial0 SUCCESS Shake:9 Replace:80 XonLimit:1024 XoffLimit:1024
64 0.00000345 fancom.exe IOCTL_SERIAL_SET_DTR Serial0 SUCCESS
65 0.00000081 fancom.exe IOCTL_SERIAL_SET_TIMEOUTS Serial0 SUCCESS RI:-1 RM:-1 RC:30000 WM:0 WC:30000
66 0.00000192 fancom.exe IOCTL_SERIAL_SET_WAIT_MASK Serial0 SUCCESS Mask: RXCHAR RXFLAG CTS DSR RLSD BRK ERR RING
67 30.00755135 fancom.exe IOCTL_SERIAL_WAIT_ON_MASK Serial0 SUCCESS
68 0.00000353 fancom.exe IOCTL_SERIAL_SET_QUEUE_SIZE Serial0 SUCCESS InSize: 8192 OutSize: 100
69 29.99287343 fancom.exe IRP_MJ_WRITE Serial0 TIMEOUT Length 1: .
70 0.00000349 fancom.exe IRP_MJ_FLUSH_BUFFERS Serial0 SUCCESS
71 0.00000985 fancom.exe IOCTL_SERIAL_SET_WAIT_MASK Serial0 SUCCESS Mask:
1 answers
solution1
0 ACCPTED 2013-04-24 18:42:21
PortMon输出\\ n的句点。
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