Astrophotographers like to use a lot of different bits of software on their observatory computers. If you use more than one piece of software that attaches to your telescope mount, then you can save a lot of time, effort and mistakes by using an ASCOM hub.

A lot of technically minded astronomers dislike ASCOM, but I fail to see what their problem is. I use a lot of different software packages on my observatory computer, and they all talk seamlessly to the telescope mount using an ASCOM hub.

Normally, when you run your planetarium software e.g. Skymap , you configure it to attach to your telescope mount. Perhaps a Meade mount on COM1. Alternatively, you can connect with an ASCOM driver for your mount. Both normally work fine. Now, if we also want to connect a third part guiding software package to the mount (e.g. Guidedog) then we have a problem - only one piece of software can connect to the mount at once. This means a lot of tedious disconnecting and reconnecting different bits of software.

This is where an ASCOM hub comes in. The hub software is a type of ASCOM component which connects to your telescope mount, and then all the other software (guider, control pad, planetarium etC) connect to the hub - and multiple bits of software can connect to the ASCOM hub at the same time. This means your guider and your planetarium software can both be permanently attached to the mount.

The standard ASCOM install comes with an ASCOM hub - this is called POTH - which stands for Plain old telescope hub/handset. Using POTH connecting to my mount I can share the mount connection between four other bits of software.

It is very easy in the heat of the astrophotographic battle to make mistakes. Using an ASCOM hub reduces mistakes and makes the whole process less frustrating.

POTH is 100% reliable, but can be a bit tricky to setup - I found it can be sensitive to the order in which you startup the different software packages - I always start with Skymap first!