Check Rx/Tx on Serial Ports
Use this procedure to check serial communication connections.
Prerequisites
Any system with serial communications, including:
Transverse Moisture Meter
Transverse HD Moisture Meter
Inline Moisture Meter
Voltage meter
Check Serial Communications Connections
STEP |
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| 1 |
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| 2 | Place the black (negative) lead to ground (Gnd). |
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| 3 | Place the red (positive) lead on the green wire (Rx). |
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| 4 | CHECK RX You should read approximately -6vdc to -9 vdc. The voltage MUST read negative for it to be accurate.
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| 5 | Now place the red lead on the white wire (Tx), while leaving the black lead on ground. |
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| 6 | CHECK TX You should now read approximately -9 vdc and -12 vdc. The voltage MUST read negative for it to be accurate. |
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| 7 | If you read less than negative 5 vdc on either wire, note the position of the wires and remove the wires. |
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| 8 | With no wires connected and the black lead on Gnd, and with the red lead on V+ you should get either 5vdc or 12vdc depending on your jumper settings. With the red lead on Rx you should get less then 1 vdc. With the red lead on Tx you should get between -10vdc and -12vdc. |
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| 9 | If these are all correct, swap the Rx and Tx wires to the other connection and read them again. |
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| 10 | If you are still not getting the correct voltages, place the wires where you had the highest negative readings and check your software settings. |
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| 11 |
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