[App_rpt-users] GM300

Steve Agee n5zua at earthlink.net
Fri May 10 17:14:00 EDT 2013


Gotcha. Not sure if you mentioned if yours was a 16 channel or not. If an 8 
channel, the above link lists pin 4 as a spare, and instructs that pin 8 
should be used for COR active low. Since you mentioned getting voltage out 
of pin 4, I'm assuming yours is a 16 channel radio. Folks with an 8 channel 
model would not have the option you are using.


----- Original Message ----- 
From: "Bill Hurlock" <bill.hurlock at cpcomms.com>
To: <app_rpt-users at ohnosec.org>
Sent: Friday, May 10, 2013 3:54 PM
Subject: Re: [App_rpt-users] App_rpt-users Digest, Vol 51, Issue 9

> Here is a clip about PIN 4 in the Accessory plug of a GM300.
> 4 Programmable Output Only This is a radio output port. It is an open 
> collector output which saturates to A+ supply when active. It is normally 
> used to drive an external relay or sense lead. It duplicates the function 
> of J3-3 of the five pin logic board. When active it can source a maximum 
> current of 250 mA.
> The pin has a 10 K ohm resistor pull-down to ground on the logic board. 
> and uses a PNP transistor to switch it up to 12V. This pin does not work 
> as an active low pin (i.e. pulling something to ground), only as an active 
> high (that is dragging something up to +12v). If you want an active high 
> output to drive a reed relay which has the other side of the coil to 
> ground, this is your pin (but don't forget to check that the backwards 
> diode is present on the coil pins).
> Bill Hurlock

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