CNC : Computerzed Numerical Control. CNCs are used widely in Automotive, Defense, Aeronautic, Sheet metal Industries  for metal cutting.

DNC : Direct Numerical Control or also called Distributed Numerical Control. It is a data link between PC & CNC machine.

Wired DNC : DNC system with PC based  Software & RS-232 data cable or Ethernet data cable & associated hardware.

Wireless DNC : Wireless link between a PC & a CNC.  It could be with one PC & multiple CNCs also.

CNC Networking :  To interface multiple CNC machines with a common PC, normally called as DNC-PC.

CNC Code Loader :A portable electronic device, capable of loading & un-loading CNC code (Text data)  from CNC.  PLC  program, NC Parameters can also be taken thr' RS-232 port. 

Baud Rate : Baud rate is bits / seconds. It is a rate at which the data is being sent on RS-232 port.

ISO / EIA Code  : A standard of CNC data. ISO code always has EVEN Parity, while EIA has ODD parity while sending the dat on RS-232 port. Most of the newer CNC use only ISO codes.

RS-232 parameters :  The basic parameters to be set are - Data bits(7 or 8) , STOP Bits ( 1 or 2), Baud Rate (300 to 1,15,200), Parity (EVEN, ODD, or NONE), Code (ISO or EIA or ASCII), End Of Block ( CR, or CR-LF, or LF), Hand Shake ( Hardware Handshake by RTS-CTS, or Software Handshake like X-on - X-off)

RS-232 Port :  It is a universal serial port for data transfer. In telecommunications,  RS-232 (Recommended Standard 232) is a standard for serial binary data signals connecting between a DTE  (Data Terminal Equipment) and a DCE (Data Circuit Termination Equipment). It is commonly used in computers & Data collection devices. A similar ITU-T standard is called V.24.

Wi-Fi : Wi-Fi  is a wireless technology brand owned by the Wi - Fi Alliance intended to improve the interoperability of wireless Local Area Network products based on the IEEE 802.11 standards. Common applications for Wi-Fi include  internet & VoIP phone access, and network connectivity.  The Wi-Fi Alliance is a consortium of separate &  independent companies agreeing to a set of common interoperable products based on the family of IEE 802.11  standards. The Wi-Fi Alliance certifies products via a set of established test procedures to establish interoperability. Those manufacturers that are members of Wi-Fi Alliance whose products pass these interoperability tests can mark their products and produc packaging with the Wi-Fi logo.

IEE 802.11 : IEEE 802.11 is a set of standards for Wireless Local Area Network (WLAN) computer communication, developed by the IEEE LAN / MAN Standards Committee (IEE 802) in the 5 GHz and 2.4 GHz public spectrum bands. Although the terms 802.11 &  Wi-Fi  are often used interchangeably, the Wi-Fi Alliance  uses the term "Wi-Fi" to define a slightly different set of overlapping standards. In some cases, market demand has led the Wi-Fi Alliance to begin certifying products before amendments to the 802.11 standard are complete.

Blue Tooth :  Bluetooth  is an industrial specification for wireless Personal Area Networks  (PANs).  Bluetooth is an open specification for wireless short-range communications. It transmits & receives via a short-range radio link using a globally available frequency band (2.4 GHz ISM band).  Bluetooth provides a way to connect &  exchange information between devices such as mobile phones, Laptops, PCs, CNCs, PLCs  over a secure, globally unlicensed short-range Radio Frequency. The Bluetooth specifications are developed &  licensed by the   Bluetooth Special Interest Group.

Telnet COM Port Control Protocol : It is a a public protocol known as specified by IETF RFC 2217. COM Port Control is an extension of the Telnet protocol. See more in FAQ as regards this protocol in SENA Products.

so it will only be available if the users try to connect to SENA Device Server using the telnet terminal that supports COM Port Control Protocol or SENA's COM Port Redirector, Serial/IP is configured to use Telnet. During the connection attempt, the terminal or serial/IP will always request that the connection use COM Port Control. If Sena Device Server agrees to use COM Port Control, only then will it become active on the current connection to the Device Server. The Serial/IP redirector indicates a successful negotiation of COM Port Control by displaying three extra "lights" next to the active COM port name in the Port Monitor window.

The COM Port Control protocol includes a number of features. The set of protocol features that are supported have proven sufficient for nearly all applications with a need for some degree of port control.
Sena Device Servers, PS110/410/810, SS100/110/400/800 and STS800/1600 with Tactical's Serial/IP redirectors use the COM Port protocol to provide the following port controls:
Baud rate (e.g., 9600)

Data Length (e.g., 8 bits)

Parity bit (e.g., none)

Stop bits (e.g., 1 stop bit)

DTR signal (often used to disconnect a call)
Serial/IP redirector use the COM Port protocol to report the following port conditions:

DCD (signals that a call succeeded)

DSR (signals that the modem is ready)

RI (signals that the phone is ringing)