| ??? 10/19/08 14:56 Read: times |
#159208 - It is a handheld terminal Responding to: ???'s previous message |
Jan Waclawek said:
... and how? You mention a battery-powered device, which would indicate, that the MAX232-side gets never connected to anything earthed, correct?
RX,TX,GND are the only three wires connected across. There is no possibility of interchanging RX and TX wires since the interconnecting cable has soldered 9 pin connector on one end and crimped RJ11 on the other end(hand held terminal side). The hand held terminal is sometimes powered from an AC adapter.This AC adapter uses a 2 pin plug to connect to 230V power source. Jan Waclawek said:
The MAX232 I have seen failed were invariably subject to some severe abuse, e.g. lightning nearby etc. Once one my colleague while fiddling around a mains-powered prototype, pulled inadvertently a 230V live wire out of a loose screw terminal and it touched a serial line. The level shifter in PC (75232 or alike) simply blasted off the PC, leaving only its legs behind... ;-) Whether JW PS. What's the state of the SECOND receiver in a failed circuit? PS2. I assume you made absolutely sure that the failure is in the MAX232 and not the circuitry connected to RxOut...? There is no other circuitry failure other than MAX232. About second receiver, I have not checked. Will check. |
| Topic | Author | Date |
| MAX232 failure | 01/01/70 00:00 | |
| MAX232 failure | 01/01/70 00:00 | |
| Does that mean, ... | 01/01/70 00:00 | |
| Yes, ground is not connected | 01/01/70 00:00 | |
| exactly what is connected to the MAX232... | 01/01/70 00:00 | |
| But it truly should... | 01/01/70 00:00 | |
| Thanks for your suggestion | 01/01/70 00:00 | |
485/232 with 'unreliable' ground | 01/01/70 00:00 | |
| It is a handheld terminal | 01/01/70 00:00 |