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roaming | You cannot supply power to the 132 through the serial connection on the 277885A1 cable. It is physically not possible, which is why Trimble provides separate power/ground leads.
A gender bender will do nothing except change the gender of the connections. If a pin was Tx, it will still be Tx after changing the gender. If it carried 12v, it will still carry 12v. If the Insight/PF3000 are male connectors (pin terminals), then you do not need a gender changer to connect the 277885A1 cable (socket terminals).
A standard null modem cable is wired something like this:
1 & 6 - 4
2 - 3
3 - 2
4 - 1 & 6
5 - 5
7 - 8
8 - 7
All you need are pins 2, 3, and 5. Pin 4 on the PF3000/Insight supplies 12v. If you connect 277885A1 to the PF3000/Insight (with gender changer or without), you will be sending 12v to the receiver on pin 4. According to the serial standard, this pin is supposed to be available to let other devices know that the receiver is ready to communicate; I don't think Trimble actually uses this pin. Regardless, it is not intended to accept a 12v input. If you connect a null modem to the AL device, then the 277885A1 to the null modem, you will end up sending 12v to pins 1 and 6 on the receiver side. Pin 1 is not used, and pin 6 should be available again to complete "handshaking" with a connected device, if Trimble chooses to use it. I'm not sure they do. But it is not made for 12v input either. What will happen if you put 12v into either pin 4 or pin 6? I don't know, maybe nothing. But I'm pretty sure I wouldn't risk ruining a $3500 receiver to find out.
As I see it, the only safe way to connect your 277885A1 cable to the Insight/PF3000, is to ensure that only pins 2, 3, and 5 are actually connected to the monitor. You can thank AgLeader for corrupting the serial standard to suit their own needs. I understand that it simplified their development/hardware work, but it makes for unnecessary complication on the user end of things. The kind of adapter Ted mentioned in an earlier post probably doesn't cost more than $25 to build, and would eliminate all possibility of unintentionally frying the receiver.
If Ag Leader is sure that connecting a null modem is all you need to do, and it will definitely positively not fail your receiver, feel free to try it. I'd make sure to get the tech's name first, and make sure he has run it past his supervisor or someone else who has the authority to buy you a new receiver if for some reason the results aren't quite what they expect.
Again, maybe AL has done this before and they know that 12v to pin 4 or 6 isn't going to hurt anything. I don't know that, so I'm suggesting a sure-fire safe alternative. | |
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Torn or Tedbear
