User manual

Publication 1797-6.5.1 - April 1999
6-6 Applying FLEX Ex Analog I/O Modules
I/O
The 1797-IE8 and 1797-OE8 modules comply fully to and provide simple
entity parameters. These modules can directly interface with a wide variety
of intrinsically safe controls and instrumentation. Because all field device
power is supplied directly from the I/O module, no extra wiring or power
sources are needed in a hazardous area.
Finally, these modules maintain intrinsic safety in hazardous areas by
providing isolation from other modules in the system as well as intrinsic
safety segregation between channels on the same module.
Optimize Power Distribution
Your FLEX Ex system must use adequate power supplies to support the
physical locations determined earlier in this chapter. Each FLEX Ex I/O
module in the system is rated for input power, and the FLEX Ex power
supply is rated in the number of output channels and power available from
each channel.
Assigning Power Supplies
Note the amount of power each module requires and assign it to a power
supply output. Continue to assign modules to the power supply output until
the supply’s output power rating is consumed. The graphic below shows the
number of modules per power supply output.
Important:Each power supply output in the FLEX Ex system is rated for
8.5W. Modules can be attached to the output until their
combined power equals that number. Do not exceed the power
supply maximum of 8.5W.
Modules
0
5
3
2
1
4
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
IRT8
1.6W
41661
IBN16
2.8W
IBN16
2.8W
IBN16
2.8W
IBN16
2.8W
IBN16
2.8W
IBN16
2.8W
IBN16
2.8W
IJ2
4.25W
IJ2
4.25W
IJ2
4.25W
IJ2
4.25W
OE8
6.3W
IE8
7.5W
ACNR
8.5W
RPFM
(In RPA)
RPFM
(In RPA)
RPA
8.5W
Modules Per Power Supply Output