https://www.asmag.com/project/resource/index.aspx?aid=16&t=secutech-made-in-taiwan-products-and-solutions
Product Info
AVerMedia POS Integration

AVerMedia POS Integration

AVerMedia Technologies
Region: Taiwan
Update: 11/13/2012
Key Specifications

Compatible with: AVerDiGi NV Series
* Input: RS-232 port from POS
* Input: Parallel port from POS
* Output: RS-232 port to printer
* Output: Parallel port to printer
* AVerDiGi POS Capture Box
* Output: RS-232 port to DVR
* Output: RS-485 (9600 to 19200bps)
* Baud Rate Setting: 9600, 19200, 57600, 115200 bps
* DC IN: DC 5V, 2A

There are two kinds of serial cable: Straight pass-through and Null-Modem. If you are connecting the POS system directly to the DVR, you need to use Null- Modem cable.

If you are using the POS Capture Box, you need to use the straight pass-through cable provided with the POS Capture Box. If you are using no flow control or software flow control, we recommend using the Null-Modem serial cable without handshaking. If using hardware flow control, we recommend using loop back handshaking.

https://www.asmag.com/project/resource/index.aspx?aid=16&t=secutech-made-in-taiwan-products-and-solutions