Rockwell Automation Liqui-Flo DBT Reach Drive - Manual (Page 26)

2-20 DBT Reach Drive User Manual
When the “Mode” switch is up (open) the board uses the digital input as an
enable/reset. When the board’s digital input is inactive (open or ground), the analog
output is held at the first channel. When the digital input is active (24V), the
microcontroller sequentially cycles through the eight temperature sensor channels.
Each channel is available at the analog output for the selected period of time. After the
eighth channel is completed, the cycle begins again with the first channel.
Deactivating the digital input will asynchronously reset the sequence back to the first
channel. The “Period” jumpers/dip switches select one of four time periods between
temperature sensor channels.
When the “Mode” switch (S2-1) is down (closed) the board uses the digital input as an
external clock to sequentially cycle through the eight temperature sensor channels.
The analog output channel advances with both the rising and falling edges of the
digital input. In both modes the active channel is output as a 3-bit binary address on
the RTD board’s digital outputs. An inactive output (open) indicates a “0.” When using
the digital input as an external clock, it may be necessary to monitor the address lines
in order to maintain synchronization with the controller. When using the internal clock
mode, the digital outputs may be ignored to reduce the required number of I/O. In
either mode, the board’s digital input is debounced with a period of 50mS.
Table 2.9 – Microcontroller Settings
Period S2-2 S2-3
1 second Down Down
10 seconds Up Down
30 seconds Down Up
60 seconds Up Up