Serial Port Issue Rx is working Tx is not Working.
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In my system one serial port available. In that I can receive data from other device but I can't send the any data from PC to Machine. I was check following. 1. Cable is working or not. [It is working in other system] 2. Device is working or not. [It is working in other system] 3. software is working or not. [It is working in other system] How can i come out from this problem please help me. Thanks in advance.
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In my system one serial port available. In that I can receive data from other device but I can't send the any data from PC to Machine. I was check following. 1. Cable is working or not. [It is working in other system] 2. Device is working or not. [It is working in other system] 3. software is working or not. [It is working in other system] How can i come out from this problem please help me. Thanks in advance.
Hi, You provided insufficient information to work on. Here are some of the possibilities: 1. your cable or target device is unreliable, it works only sometimes. 2. your voltage levels don't really match; the machine it is not working on is not getting at a sufficient voltage level (may well happen with cheap and/or long cables). 3. your transmitter is defective. 4. your transmitter is programmed in such way that it requires a "go ahead" signal to start transmitting; i.e. you have enabled dataflow control (either by hardware DTR/DSR/CTS/RTS or by software CTRL/Q or equivalent), and the target (or the cable) is not providing the go ahead. etc. There are two ways to get this solved: 1. accurate observations, using voltmeter, oscilloscope, whatever it takes to get real facts. 2. using redundant equipment: have a short null-modem cable and let this PC talk to another one (use HyperTerminal), to verify the port transmits at all. Then include your current cable. etc. :)
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In my system one serial port available. In that I can receive data from other device but I can't send the any data from PC to Machine. I was check following. 1. Cable is working or not. [It is working in other system] 2. Device is working or not. [It is working in other system] 3. software is working or not. [It is working in other system] How can i come out from this problem please help me. Thanks in advance.
What kind of device are you connecting to? If its another PC you need a null modem cable that swaps Rx and Tx, and ties RTS to CTS (assuming you are using handshaking) and depending on your target hardware asserts DCD/DSR, etc. If you haven't gotten this working yet and you need more help, please provide some more details.