CommsMode

This optional parameter is left blank when used with the SDM-SIO1A or SDM-SIO4A. The CommsMode specifies the configuration of the datalogger's control port used by this instruction. The ports can also be configured using Device Configuration Utility. Configuring the ports using the SerialOpen instruction will change the setting if it was previously set by other means.

Code	Description
0	Configures the port as RS-232, 5V and -5V voltage levels (ComC1-ComC7, and CPI/RS-232 )
1	Configures the port as TTL, 5V and 0V voltage levels ( ComC1-ComC7)
2	Configures the port as LVTTL, 3.3V and 0V voltage levels ( ComC1-ComC7 )
3	Configures the port as RS-485 half-duplex, PakBus communication (ComC1, ComC3, ComC5, or ComC7; Odd ports = A-; Even ports = B+)
4	Configures the port as RS-485 half-duplex, transparent (ComC1-ComC7 only; Odd ports = A-; Even ports = B+)
5	Configures the port as RS-485 full-duplex (ComC1 or ComC5 only; requires 4 adjacent control ports For ComC1, C1 = TX-, C2 = TX+, C3 = RX-, C4 = RX+). For ComC5, C5=TX-, C6 = TX+, C7=RX-, C8=RX+)
6*	RS-485 TX only. In this configuration the transceiver is left on so the A(-) and B(+) idle in a marking state (logical '1').
7*	RS-422 full-duplex transparent. In this configuration, the transceiver for the transmit pair is left on. The transmit pair A(-) and B(+) idle in a marking state (logical '1').
*	Optional parameter added in OS 8.00 and newer.