DELTA TAU ACC-51E Input/Output Module Multi directional Channels

When CS handshaking is used (I1 is 0 or 2), Turbo ACC-51E waits for the CS line to go true before it will send a character. This is the normal setting for real serial communications to a host; it allows the host to hold off Turbo ACC-51E messages until it is ready. When CS handshaking is not used (I1 is 1 or 3), Turbo ACC-51E disregards the state of the CS input and always sends the character immediately. This mode permits Turbo ACC-51E to “output” messages, values, and acknowledgments over the serial port even when there is nothing connected, which can be valuable in stand-alone and PLC-based applications where there are SENDS and CMDS statements in the program. If these strings cannot be sent out the serial port, they can back up, stopping program execution.

When software addressing is not used (I1 is 0 or 1), Turbo ACC-51E assumes that it is the only card on the serial line, so it always acts on received commands, sending responses back over the line as appropriate. When software addressing is used (I1 is 2 or 3), Turbo ACC-51E assumes that there are other cards on the line, so it requires that it be addressed (with the @{card} command) before it responds to commands. The {card} number in the command must match the card number set up with variable I0.