What is the asterisk at the end of each line of G-Code?

Controllers Smoothie
1

I am building a Cartesian 3D printer that looks like the Bukito using an Azteeg X5 Mini Smoothie Board with Repetier Host (V1.5.4) and eventually a E3D V extruder. I have some NOOB/newbie/dumb questions. I am trying to get my printer to Home properly (Z homing works great, X homing so-so and Y homing not at all). I am trying to understand the G-Codes that R-Host is sending my printer. For example, when I click on the Y Home icon, R-Host sends the following lines of code :

12:07:06.349 : N112 G91 *51
12:07:06.349 : N113 G1 Y1 F600 *19
12:07:06.349 : N114 G90 *52
12:07:06.349 : ok

Question 1 : I have done extensive searching but could not find what the *51, *19 and *52 at the end of each line mean? (I have no problem with all the other G-Codes - I teach CNC machinists in a trade school in Montreal)
Question 2 : what relation/priority exists between R-Host and the Config file on the micro SDCard? Does R-Host take into consideration changes made to the Config file? or do the parameters in R-Host override the Config params?

Any help would be appreciated.

Lorne Wilkins

Imported from wikidot

2

The asterisk thing is to check the message was properly sent/received, see http://reprap.org/wiki/G-code#.2A:_Checksum

I’m not sure what you mean about relation/priority of config options, I don’t know that there are any that are really in common between the host and smoothie …

3

ok thanks for your quick reply

Lorne Wilkins