When you turn your printer on, you will often come to this tab. The above picture shows the tab after connecting with the printer. At the top you see the most important printer status, so you always know what is happening.
The next row allows it to send any g-code command you like. Enter it and press return or hit the send button. With the cursor up/down keys you can move through the history of manually send commands.
The next block controls the positioning of the extruder. With the arrow keys you move the extruder in any direction. When you hover over the arrow, you will see a distance appear, telling you how large the move will be. Near the positive axis you see the current extruder position. After the connection, they are red. Red means the host has no idea where the extruder really is. Press the home button to move the extruder to its defined position. After that the color turns black, telling you the position is known. From now on, the moves are only possible inside the printer cube defined in the printer settings. So if you are at x=180 and the cube is 200mm wide, pressing 100m right will only move to 200mm.
CAUTION: This protection works only for the arrow keys! Sending a G1 X300 would really send this to the printer. After that the host will show the coordinate in red again, assuming the move didn’t succeed.
Below the arrows you have the following buttons:
Power: This turns the power supply on. This is not supported from all boards and needs a ATX power supply.
Stop motor: Will disable the stepper motors.
Park: Moves the extruder head into parking position defined in printer settings.
The “Speed multiply” slider allows it to change the printing/move speed in relation to the send feed rate. This function is tested with Repetier-Firmware and Marlin. Be careful if you increase the speed. If you haven’t defined the real limits in your firmware this can cause lost steps during print!
The extruder and print bed blocks allow it to change the temperature. The button indicates, if the heating is turned on (green). If it is, the value entered as temperature is set. To the left you see the last read temperature (you have enabled automatic temperature reading in printer settings?). With the arrows you can change the temperature. If you change it in the text field, you need to press return or leave the field to set the value. In the extruder box, you can also extrude and retract filament, which is handy if you switch filament or to refill the nozzle with fresh filament.
If you have a fan attached, you can change the fan speed with the slider in the fan box.
In the last row you can set debug options for the printer. Echo repeats the received lines, so you normally want it turned off. Info and error show messages at that debug level. These are interesting, so leave them on. The last one is something special, which works up to now only with Repetier-Firmware. In dry run mode, the firmware will ignore all commands to set temperature or extrude. That way you can send a file without using any filament. This is handy if your printer loses steps during print and you are doing some research on when and why. If you seem to have troubles with your extruder, check if you have that option enabled! The last button “ok” fakes a receiving ok from the printer. If your printer stalls, it may be simply because the firmware send an ok and only the o or k was received. In that case, hitting ok can restart the printing process.