The BLS series is a complete line of high-performance RS-232, RS422/485 and current loop cards, as well as "All-in-One" cards which include all the above protocols on a single card. All cards come with 16C550-style UARTs which feature 16-byte transmit and receive buffers to help guard against loss of data in your busy system. All cards may be addressed as COM1: to COM4: or any other I/O address you choose from 000 up to 3F8 hex. All cards use one or more standard DB-9 male (9-pin) connectors (video controllers have DB-9 female connectors). All ports are capable of operating at speeds up to 460kbaud simultaneously, making these units ideal for high-speed applications such as ISDN modems.
Powerful All-in-One models feature RS232, RS-422.485, and Current loop, all in one card. You pick which protocol you want to enable. Model BLS AN11S is MetraByte™ COM-422 compatible with the additional capability of RS-485 operation. The BLS AN12S is a dual-port version with additional interrupts available. Ports are configured independently for the protocol you wish to use.
Current loops are switch-selectable for active or passive operation. These cards are the top of the line for multi-port current loop operation. Units feature a guaranteed OFF state of less than 2 milliamps of loop current.