8
Digital Inputs
The MyDro digital inputs feature software selectable wire fault supervision.
That means the end-of-line (EOL) resistors are optional. When the no-fault (NF)
setting is chosen at the LCD digital input “Config.” screen, no EOL resistors
should be installed.
Multiple sensors connected to the MyDro digital input can be wired to
(share) a common (chassis) ground. The Legacy series required 1,800
ohm resistors wired in series as described in Appendix C of the M110/
M800 Installation Manual.
See I/O Expansion section for expanded digital information.
Note:
For EOL resistors to be effective they must be installed parallel to
the sensor switch, not on the terminals of the RTU.
Wet Well Module
Legacy series RTUs support the Wet Well Module (WWM) by way of the RJ45
interface on the left side of the printed circuit board. There were two versions of
the WWM (green, older and red, newer).
The MyDro does not directly support
either version of the WWM, but does support the optional Safe Module Plus
via the RJ45 (RS485/Modbus port).
The WWM provided two primary functions —that of pump run indication and that
of sharing the signal of the high-level float to both the Mission RTU and the local
panel (local siren). While the MyDro does not support the WWM the cable from
either version can be cut and terminated directly to the MyDro terminals. If you
currently utilize local alarming and want to continue doing so, you may consult
Figure 1 to reuse the WWM.
Furthermore, the newer, red version relies on the load sensors that are now directly
supported on the MyDro. In other words, you could chose to directly wire the load
sensors to the MyDro as indicated in the standard MyDro installation manual and
continue to use the float functionality of the WWM.
