For us to transfer .dst stitch files to our SWF machines we use a 9 pin null modem cable with female connectors on both ends.
The standard computer uses a male 9 pin connector for its serial port. It’s the same for SWF embroidery machines.
Null Modem Cable
A null modem cable is frequently called a crossover cable. It is used to allow two serial Data Terminal Equipment (DTE) to communicate with each other without using a modem in between. For this to happen, the Transmit pin of one device is connected to the Receive pin of the other device. To enable hardware handshaking between the two devices, the Request to Send pin of one device is connected to the Clear to Send pin of the other device. Because these pins are “crossed” on the two cable connectors, the term crossover cable was given.
Pin Functions for RS-232 Data
TX (pin 3 ) Serial Data Output
RX (pin 2 ) Serial Data Input
RTS (pin 7 ) Request to Send
CTS (pin 8 ) Clear to Send
DSR (pin 6 ) Data Set Ready
DCD (pin 1 ) Data Carrier Detect
DTR (pin 4 ) Data Terminal Ready
GND (pin 5) Ground
Null Modem Cable with Full Handshaking 2 variations
RX 2:———————–:3 TX
TX 3:———————–:2 RX
DTR 4:——————–:6 DSR
GND 5:——————–:5 GND
DSR 6:——————–:4 DTR
RTS 7:——————–:8 CTS
CTS 8:——————–:7 RTS
RS232 serial communication protocol
RS232 is the most common serial interface and is standard on most Windows compatible desktop computers. It only allows for one transmitter and one receiver on each line and uses a Full-Duplex transmission method. RS232 is used for many purposes, such as connecting a mouse, printers, scanners or modems, as well as industrial instrumentation. With improvements in line drivers and cables, applications often increase the performance of RS-232 beyond the distance and speed listed in the standard.
Com Port Settings for SWF machines
Data Bits: 8
Stop Bits: 1
Just for some clarity DTE, DCE
DTE – Data Terminal Equipment; DCE – Data Communications Equipment.
DTE and DCE are the two sides of an RS-232 interface. It is important to differentiate between the two because the pin outs for the cables are physically different, as are the handshaking process and interfacing. A modem is an good example of a DCE device. And a common DTE device is the serial port on a computer.
Wiring a DTE device to a DCE device for communication is easy. The pins are a one-to-one connection. A straight through cable is commonly used for this application. In contrast, wiring DTE to DTE requires crossing the transmit and receive wires. This cable is known as a null modem or crossover cable.