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8-Port RS-232/422/485 serial communications board
DNx-SL-508
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4-port, RS-232/422/485 serial communications board
DNx-SL-501
![4-port, synchronous serial communications, HDLC, and SDLC protocol support](https://www.ueidaq.com/uploads/uei_product_io_dna_sl_504.jpg)
4-port, synchronous serial communications, HDLC, and SDLC protocol support
DNx-SL-504
![4-port, RS-232/422/485 serial communications board 4mbs](https://www.ueidaq.com/uploads/DNA-SL-501-blue.jpg)
4-port, RS-232/422/485 serial communications board 4mbs
DNx-SL-501-804