Campbell Hausfeld SDM-SIO4 manual Parity Bits, Serial Handshake Modes

SDM-SIO4 4-Channel Serial I/O Interface

B.4 Parity Bits

Parity can be enabled and set to either odd or even.

0.No parity set

1.Odd parity set

2.Even parity set

B.5 Serial Handshake Modes

You can select different kinds of handshaking from none at all, hardware (DTR, CTS etc.) and XON/XOFF. On modes 0 and 1 there is a user-set delay (0..254 x 50ms) between CTS being set and data being sent; this allows time for sensors to power up.

0.Leave as previously set.

1.DTR is always set as the SDM-SIO4 is always ready for data. RTS is set when data is ready to transmit. Data is transmitted following a delay (n x 50ms) after CTS is set; transmission stops if CTS falls.

2.DTR and RTS are always set. Data is transmitted following a delay (n x 50ms) after CTS is set; transmission stops if CTS falls.

3.DTR and RTS are always set; ignore CTS.

4.XON/XOFF software handshake. The SDM-SIO4 will XON again if no more XOFFs are sent after a time-out of n x 50ms. This mode is only functional for data transmissions from the SDM-SIO4. If an RS232 device sends large amounts of data and it can only be controlled by XON/XOFF techniques it must be implemented from within the datalogger program (by using datalogger instructions to send the stop and start characters).

9.No automatic handshaking. The datalogger can read, set or clear RTS and DTR under datalogger program control; this is effectively ‘manual’ handshake control.

Delay – this is the delay referred to above. It is entered in 50ms steps. Values in the range 0..254 are acceptable. The accuracy is -50ms, +0ms.With XOFF/XON, 255 is a special case as indicated below.

NOTE If the delay is set to 255, then the SDM-SIO4 will stay in the

XOFF state indefinitely, until an XON is received.

B-2