Omron NX-EC0112, User Manual

Page: 88 / 468

4 Installation and Wiring
4 - 10 NX-series Position Interface Units User’s Manual (W524)
The total current consumption from the I/O power supply from the NX bus must be less than the maxi-
mum I/O power supply current of the Communications Coupler Unit or Additional I/O Power Supply
Unit.
To confirm this and to calculate the I/O power supply capacity, calculate the total current consumption of
the I/O power supply from the NX bus.
The total I/O current consumption from the NX bus is the sum of the following: the current consumption
from the I/O power supply for the NX Units that receive power from the I/O power supply from the NX
bus, the current consumption of those I/O circuits, and the current consumption of connected external
devices.
Calculate the total current consumption from the I/O power supply for the Position Interface Units as fol-
lows:
• Total Current Consumption for an Incremental Encoder Input Unit
= (Current consumption from I/O power supply of Unit) + (Total input current for Unit voltage inputs) +
(Total current consumption of connected external devices
*1
)
• Total Current Consumption of an SSI Input Unit
= (Current consumption from I/O power supply of Unit) + (Total current consumption of connected
external devices)
• Total Current Consumption of a Pulse Output Unit
= (Current consumption from I/O power supply of Unit) + (Total input current for Unit voltage inputs) +
(Total load current of loads connected to Unit outputs) + (Total current consumption of connected
external devices)
Refer to A-1 Datasheets on page A-2 for the current consumption from the I/O power supply for the indi-
vidual Position Interface Units.
*1. If you use the 5-V power supply for an encoder, be sure to include that current too. Refer to A-1 Datasheets
on page A-2 for the method to convert a 5-V power supply current consumption to a 24-V power supply cur-
rent consumption.
The Communications Coupler Unit supplies the NX Unit power and I/O power to the NX Units in the
Slave Terminal. The following three Units are related to power supply for the NX Series other than the
Communications Coupler Units.
• Additional NX Unit Power Supply Unit
• Additional I/O Power Supply Unit
• I/O Power Supply Connection Units
Refer to the NX-series System Unit User’s Manual (Cat. No. W523) for the specifications of these Units.
For a complete list of the latest power supply Units in the NX Series, refer to the product catalog or offi-
cial website, or contact your OMRON sales representatives.
The following sections describe each of these Units.
4-2-3 Calculating the Total Current Consumption from I/O Power Sup-
ply
4-2-4 NX-series Power Supply-related Units