Series 655T/656T Transmitter User's Manual mV/TC Input
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Mounting
Refer to Enclosure Dimensions Drawing 4501-780 for
mounting and clearance dimensions.
DIN Rail Mounting:
This module can be mounted on "T" type
DIN rails. Use suitable fastening hardware to secure the DIN rail
to the mounting surface. Units may be mounted side-by-side on
1-inch centers for limited space applications.
"T" Rail (35mm), Type EN50022:
To attach a module to this
style of DIN rail, angle the top of the unit towards the rail and
locate the top groove of the adapter over the upper lip of the rail.
Firmly push the unit towards the rail until it snaps solidly into
place. To remove a module, first separate the input terminal
block(s) from the bottom side of the module to create a clearance
to the DIN mounting area. Next, insert a screwdriver into the
lower arm of the DIN rail connector and use it as a lever to force
the connector down until the unit disengages from the rail.
Electrical Connections
Terminals can accommodate wire from 14-24 AWG, solid or
stranded. Since common mode voltages can exist on signal
wiring, adequate wire insulation should be used and proper wiring
practices followed. Input wiring may be shielded or unshielded
twisted-pair. Output wires should be twisted pair. Strip back wire
insulation 1/4-inch on each lead before installing into the terminal
block. It is recommended that output wiring be separated from
the input wiring for safety, as well as for low noise pickup. Note
that each channel’s terminal block is of a plug-in type that can be
easily removed to facilitate module removal or replacement,
without removing individual wires. To prevent electric shock, be
sure to remove the I/O signal before unplugging the terminals to
uninstall the module or before attempting service. All
connections should be made with I/O signals removed.
CAUTION:
Risk of Electric Shock - More than one
disconnect switch may be required to de-energize the
equipment before servicing.
1.
Input (Each Input):
Connect input(s) per Electrical
Connections Drawing 4501-778. Observe proper polarity
when making connections.
2.
Output/Power Connections (Each Output)
: Connect a DC
power supply and load in a two-wire configuration as shown
in Electrical Connections Drawing 4501-778. Loop current is
input to the OUT+ lead and returned via the OUT- lead.
These transmitters operate from DC supplies only. Power
supply voltage is not critical and should be from 12-36V DC.
Further, the power supply voltage must be adequate to
supply full-scale current to the load, plus 12V to the
transmitter terminals, plus any transmission line drop.
Variations in power supply voltage or load resistance within
rated limits has negligible effect on transmitter accuracy.
Ripple & Noise:
Power supply ripple at 60Hz/120Hz is
normally reduced at the load by the transmitter. The ripple at
the load will generally be less than 0.02% of span per volt
peak-to-peak of power supply ripple. Connect an external
1uF capacitor across the load to further reduce this ripple if
desired.
For sensitive applications with high-speed acquisition rates,
high frequency noise may be suppressed by placing a 0.1uF
capacitor directly across the load.
Inductive Loads:
If the two-wire current loop includes a
highly inductive load (such as an I/P transducer), this may
reduce output stability. In this case, place a 0.1uF capacitor
directly across the inductive load and this will typically cure
the problem.
3.
Grounding:
See Electrical Connections Drawing 4501-778.
The module housing is plastic and does not require an earth
ground connection. If the transmitter is mounted in a metal
housing, a ground wire connection is typically required.
Connect the metal enclosure’s ground terminal (green screw)
to earth ground using suitable wire and per applicable codes.
WARNING:
For compliance to applicable safety and
performance standards, the use of twisted pair wiring is
recommended as shown in Drawing 4501-778. Failure to
adhere to sound wiring and grounding practices as
instructed may compromise safety and performance.
3.0 MODULE CONFIGURATION
This transmitter module needs to be configured for your
application. Configuration is accomplished by first setting the DIP
switches as required, then optionally re-scaling the input range to
the 4-20mA output range endpoints.
All valid input ranges have already been calibrated at the
factory. By default, the output 4mA and 20mA range end points
are factory set to correspond to the full input range endpoints, but
may be optionally adjusted to correspond to a portion of the input
range as described below. Reconfiguration of transmitter zero
and full-scale is accomplished via momentary toggle switches on
the front of the module.
DIP SWITCH SETTINGS
Adjacent to the I/O channel terminals are a bank of 12 DIP
switches used to select the input range/type, disable/enable TC
break detection, set TC break upscale or down-scale, turn CJC
On or Off, enable/disable linearization, and lock/unlock
reconfiguration. DIP switch 12 is used to optionally lockout
zero/full-scale reconfiguration and must be set ON to facilitate
zero and full-scale adjustment. Refer to Drawing 4501-779 and
Table 3 below to locate and set these switches as required for
your application (shaded entries refer to the factory default
configuration). After setting the switches, you will need to
configure the zero and full-scale input points via the front panel
toggle switches as described below. You should also install the
plastic covers (packaged separately) over the DIP switch
openings after making your settings (partial enclosure
disassembly is required). This helps protect the circuit from
penetration by ESD or debris, and prevents tampering in the field.