Help adding two estops via HAL

Hi, I have a K2 CNC linked to my computer via a Probotix Unity 2 connected to two parallel ports. ( This page with pin connections on the Unity 2 may be useful for reference)
I am using LinuxCNC version 2.7.14. I know there are newer versions, but I could not achieve an acceptable level of jitter with them, and from my research of features added 2.7.x works fine for my purposes.

The parport0 handles basic machine control (axis, limits etc) and the parport1 is connected to an MPG pendant. 

I have an estop on the pendant which works and I have specified as: 
I would like to add a second estop on parport.0.pin-15, however by my understanding simply adding a second line like the above is not possible. 

From my reading, doing this should be possible using an OR2 or an estop-latch. I have read the man pages for both, and think an or2 should be sufficient, however have been unable to fully understand how to write one for this. 

Any help would be greatly appreciated.
 

A better way would be to use estop-latch and chain two instances of it together (one for each switch).
There is an example of using one instance in the forum hal examples
For multiple instances, I usually do a little block drawing before adding it to hal

Thank you, I will give that a go!
I see the or problem now, I think that explains some of my issues.

Thank you, I will try first with AND2, and once I can get it working I will try the more proper method. Also thanks for your many helpful responses on this forum (and tommylight) I have found them invaluable while getting other parts of this project working