| ??? 10/19/08 13:46 Read: times |
#159205 - Yes, ground is not connected Responding to: ???'s previous message |
Kai Klaas said:
...that signal ground isn't connected from the "product" to the "external RS485 device"? This is a big mistake, because due to your earth potential shifts huge common mode interferences can hit the both ends of RS485 cable!
However, the external RS485 device has no provision to connect Ground line. The external RS485 device belongs to a "large" "reputed" manufacturer and they feel that lack of ground connection can not be the reason for failures as it is working in installations in some other parts of the world! One observation is: MAX485 has not failed in even one installation. All the failures are on MAX232 side. That is what is intriguing. Could this be related to the way IC is handled while soldering, due to lack of precautions as far as static electricity is concerned, since ICs are hand soldered? |
| 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 |