Rockwell Automation 44887-PUB, 44887 Enwatch - Manual (Page 6)

Publication GMSI10-UM031C-EN-E - January 2009
2 Installing the Enwatch
Installation The Enwatch unit is easy to install. The enclosure is mounted using four
screws. Cables are terminated on removable screw terminal blocks, making
installation and service simple. Network cables are terminated on the board
using a a standard RJ-45 connector.
Each Enwatch board has four status LEDs to monitor system activity. In the
unlikely event of a system problem, a portable PC can be used to diagnose the
problem using the RS-232 serial interface on each Enwatch board.
Prior to installation, the only set-up required is to assign an IP address, Subnet
Mask, and Gateway IP address (if available) to the node. This must be a unique
address on the network. You assign the IP address by connecting a terminal
(or PC in terminal mode) to the on-board RS-232 port and using the on-board
monitor program. See “Setting Up an Enwatch Unit” on page 11 for more
information.
Electrical
The circuit board is a completely self-contained 16-channel analog input to
Ethernet interface, including power regulation and local communication
facilities. A block diagram of the board is shown in Figure 1.1 on page 1. Each
block of the diagram is described below.
• ICP interface - Each of the 16 channels has its own ICP interface that
is capable of powering a typical two-wire ICP transducer. The nominal
voltage is 24 V with a constant current of 3.6 mA. A typical transducer
has a bias voltage value of around 11 V, so that the system can
accommodate a full ±10V input range. The ICP interface can be
disabled for AC and DC coupling of voltage signals.
• Multiplexer - The multiplexer circuit selects one of the 16 input
channels under software control. All inputs are over-voltage and ESD
protected.
• High pass filters - Four software-programmable high-pass filters
(0.36 Hz, 2.67 Hz, 5.3 Hz, and 23.8 Hz) are available to remove
unwanted low frequency signals.
• Integrator - An on-board hardware integrator is available for getting a
velocity measurement from an accelerometer, as well as displacement
from a velocity sensor. The host software can perform a second level of
integration if required.
• Spike Energy™ function (gSE™) - gSE provides a conditioned
signal suitable for measurement of bearing condition.
• Anti-aliasing filter - This filter removes high-frequency components
from the incoming analog signal that might alias back into the sampled
signal, resulting in incorrect data in the spectrum. The filter has a very
high roll-off and removes all alias effects in standard sampling/spectral
analysis applications.