Glossary

‘Looper’

Looper is a tool designed to be super easy to use that facilitates DNC file transfers between CNC equipment and computers on a network.

API KEY

An API key is a unique identifier that is used to authenticate requests to an API. Looper uses an API key to authenticate requests to Open Weather to get the outside local temperature. This is a cute Looper feature to display outside temperature on the LCD display while Looper is idle.

Baud Rate

The rate at which information is transferred over the serial cable. Higher baud rates allow faster data transfers.

CNC

‘Computer Numerical Control’ automated control of machining tools (such as drills, lathes, mills, and 3D printers) by means of an embedded computer which runs a user generated program written as G-code.

Data Bits

The number of data bits used to represent each character that is being sent over the serial cable. Commonly set to 7 or 8. However, must be set to 7 if parity checking is enabled.

DNC

‘Direct Numerical Control’ or ‘Distributed Numerical Control’ is a system that enables communications between a central computer and multiple CNC machines.

Drip Feed

Some Gcode programs are too large to download and fit into a CNC’s memory space. To get around that problem, many CNC machines support drip feeding the program. Looper support drip feeding Gcode programs up to 20 gigabytes in size!

Ethernet Port

A port for connecting Looper to a network via a wired connection. Most often, the Ethernet cable connects Looper to a network switch or router.

Flow Control

This is a simple protocol that uses Xon and Xoff characters to control the flow, or stream, between two serial devices. Looper can use flow control when drip-feeding programs, as an example.

G-code

G-code, also known as RS-274, is the language used to control CNC (Computer Numerical Control) machines. It consists of a series of instructions that tell the machine how to move its tools to create a specific design or part. G-code commands can specify movements (such as moving in straight lines or arcs), speeds, and tool changes, among other actions. These programs can become quite large!

Indicator - Power

On the front face-plate of Looper is a red LED that indicates power is on when illuminated. The red LED slowly fads in and out during normal operation.

Indicator - Status

On the front face-plate of Looper is a green LED, labeled ‘Status’, that flashes on new events. As an example, an event could be a new file has been downloaded over the network to Looper, or, a new DPRNT message has been captured from the CNC machine - these are just a few examples. The status indicator is handy when your located at a far distance from the CNC machine but still want to see that the file has been received by Looper.

IP Address

Every computer that wants to connect to a network needs an IP Address. An example would look like, “192.168.0.123”. Rotate the knob on the front of Looper and the LCD display will show the assigned IP Address.

Parity Checking

Using parity checking each character can be sent with a parity information. If the character and parity do not match a comm error is detected. To use parity checking, the number of data bits must be set to 7. Parity checking can be set to None, Even, or Odd.

Xmodem

Xmodem is a protocol that is used over a serial link like RS232. The protocol groups characters into packets. After each packet is sent a followup checksum is sent. If the receiver’s packet checksum does not match the protocol will retry the packet until the checksums match. This protocol is a great improvement over simply using