Used on the DYMO/CoStar LabelWriter thermal printers that connect through RS-232.
|CTS||1||-->||8||CTS||Clear to send|
|TXD||2||<--||3||TXD||RS232 Transmit (to LabelWriter)|
|RXD||3||-->||2||RXD||RS232 Receive (from LabelWriter)|
|RTS||5||<--||7||RTS||Request to send|
|DSR||6||-->||6||DSR||Data set ready|
This pinout comes from the cable that came with a CoStar LabelWriter XL Plus, tested with a multimeter. (It is likely that its the same one used for other LabelWriters made by CoStar and DYMO, but this is merely speculation.)