Series 655T/656T Transmitter User's Manual mV/TC Input
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6.0 SPECIFICATIONS
655T-0600
, Single, 2-Wire, mV/TC Isolated Channel
656T-0600
, Dual, Independent 2-Wire, mV/TC Isolated Channels
656T-E600
, Dual, Independent 2-Wire, mV/TC Isolated Channels
General:
The Model 655T/656T-0600 Two-Wire Transmitters
accept either thermocouple or voltage input(s), provide input-
to-output and channel-to-channel isolation, and generate 4 to
20mA two-wire output signal(s). The 655T-0600 unit provides
a single isolated I/O channel, while the 656T-0600 unit
provides two independent isolated I/O channels. The
economy Model 656T-E600 is similar to the 656T-0600, but
only supports the TC type J & K, and 0-125mV input ranges,
and provides no TC linearization. Units are fully configured
via external DIP and toggle switches. The transmitters are
connected in two-wire fashion with the output signal and
power sharing the same leads. These transmitters are DIN-
rail mounted with plug-in type terminal blocks. Non-volatile
reprogrammable memory within the module stores calibration
and configuration information.
MODEL NUMBER DEFINITION
Transmitters are color coded with a white label. The prefix
“6” denotes the Series 600 family of transmitters and isolators,
whil
e the “T” suffix specifies that this device is primarily a process
transmitter.
65xT:
Two-wire, single channel (655T), or dual channel (656T)
transmitters for mV/TC inputs.
-0600:
The four digits of this model suffix represent the following
options, respectively:
0 = Option specifier - 0=Standard, E=Economy Model;
6 = Output is DC current;
0 = Enclosure is DIN rail mounted;
0 = Approvals: cULus Listed, UL file E199702 &
E202242.
Hazardous Locations: Class I; Division 2; Group A,
B, C, D.
INPUT SPECIFICATIONS
Unit must be wired and configured for the intended input type
and range (see Installation Section for details). The unit can be
configured to accept any one of the input types described below
via the DIP switches. Note that economy Model 656T-E600 units
only support the TC type J & K, and 0-125mV input ranges, with
no TC linearization provided. Toggle switches on the unit are
used to scale the input to the 4-20mA output. The following
paragraphs summarize this module’s input types, ranges, and
applicable specifications.
Thermocouple
: User-configured for the eight types of
thermocouples shown in Table 5. Model 656T-E600 units
only support J & K TC types, plus the 0-125mV input range.
Linearization (separately enabled), Cold-Junction
Compensation (CJC), and open circuit or lead break
detection are included. Model 656T-E600 units do not
support TC linearization.
TC Input Reference Test Conditions:
TC Configured for a
10mV TC span (e.g. Type J at 186
C); Ambient Temperature
= 25
C; Power Supply = 24V DC, R-load=500
.
Thermocouple Reference:
Accurate to better than
0.4
C
typical at 25
C. Ambient temperature effect of the CJC
circuit is
0.01
C/
C typical.
Note:
DIP switch SW10 allows CJC to be switched off to
allow direct connection of a mV source to the input in order to
complete zero and full-scale calibration of a TC input if
desired. CJC is ignored for voltage input ranges.
IMPORTANT:
CJC temperature is only resolved to 0.1
C.
As such, units calibrated for smaller spans may appear less
accurate with CJC ON as
0.1
C becomes a greater
percentage of span. Keep this in mind when resolving
measurements with smaller spans and higher gains.
TC Linearization (Separately Enabled):
Within
0.25
C of
the NIST tables. Model 656T-E600 units do not support TC
linearization.
Table 5: TC Types, Ranges, and Accuracy
TC
Type
TC
Material
ISA/ANSI
Color
C Temp
Range
Typical
Accuracy
J
+Iron,
-Constantan
white
red
-210 to
+ 760
C
0.5
C
K
+Chromel,
-Alumel
yellow
black
-200 to
+1372
C
0.5
C
T
+Copper,
-Constantan
blue
red
-260 to
+ 400
C
0.5
C
R
+Pt/13%Rh,
-Constantan
black
red
- 50 to
+1768
C
1.0
C
S
+Pt/10%Rh,
-Constantan
black
red
- 50 to
+1768
C
1.0
C
E
+Chromel,
-Constantan
purple
red
-200 to
+1000
C
0.5
C
B
+Pt/10%Rh,
-Pt/6%Rh
gray
red
+260 to
1820
C
1.0
C
N
+Nicrosil,
-NISIL
orange
red
-230 to
-170
C;
-170 to
+1300
C
1.0
C
0.5
C
DC Voltage:
User-configured for the following DC voltage
ranges:
15.6mV,
31.3mV,
62.5mV, 0-125mV, 0-250mV,
0-500mV, 0-1.0V.
Voltage Input Reference Test Conditions:
62.5mV input
range configured with a 10mV span; Ambient Temperature =
25
C; Power Supply = 24V DC; R-load=500
.
Accuracy for mV Inputs: Better than
0.1% of span.
General Input Specifications
Input Filter Bandwidth:
-3dB at 3Hz, typical.
Input Bias Current:
25nA typical.
Noise Rejection (Normal Mode):
Better than 40dB @
60Hz, typical with 100
input unbalance.
Noise Rejection (Common Mode):
Better than 140dB @
60Hz, typical with 100
input unbalance.
Analog to Digital Converter (A/D):
A
16-bit
-
converter.
Input Filter:
Normal mode filtering, plus digital filtering
optimized and fixed per input range within the
-
ADC.