Model TT231-0600
Two-Wire RTD Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
- 38 - http://www.acromag.com
- 38 -
http://www.acromag.com
Output…
Hardware uses digitally controlled (7 bits + sign) coarse & fine DAC’s with 256 steps
of adjustment in each. Zero code output level is ~4.116mA. Coarse adjustment is
0.029mA/step with a typical coarse adjustment range from -3.77mA to +3.77mA at
the output. Fine adjustment is 0.0018mA/step for an adjustment range of -236uA to
+236uA at the output.
Output Full-Scale Adjust:
20mA nominal, adjustable from 16-24mA. Sets value
corresponding to 100% of output, and is adjusted independent of over-range
threshold. Effective adjustment range is additionally limited via the configuration
software.
Output Span:
16mA nominal (4-20mA), digitally adjustable. Span adjust is
determined by PGA gain and sensor excitation with 3 methods of digital adjustment:
PGA gain select, reference current coarse adjustment and fine adjustment. Span
expressed as Io/Vin from the PGA to the output amp has an adjustment range of
49.3mA/V to 3150mA/V. Additionally, the linear operating range of the output may
be extended via the under-scale and over-scale threshold settings set separately.
Your effective adjustment range is additionally limited via the configuration software.
Output Fault/Alarm Limits:
Downscale fault level is ~0.4mA below the selected
under-scale threshold, typical. Upscale fault level is ~1.0mA above the selected over-
scale threshold, typical. The unit can be set for limits that comply with NAMUR NE43
recommendations.
USB Interface
Includes a USB socket for temporary connection to a PC or laptop for the purpose of
setup and reconfiguration. USB isolation is required when connected to a grounded
input sensor or driver (see note at right). During reconfiguration and calibration, the
transmitter receives power from both the USB port and the output loop. Both power
sources must be present to calibrate the unit.
CAUTION:
Do not attempt to connect USB in a hazardous environment. Transmitter
should be setup and configured in a safe environment only.
Data Rate:
USB v1.1 full-speed only, at 12Mbps. Up to 32K commands per second.
USB 2.0 compatible.
Transient Protection:
Adds transient voltage protection on USB power & data lines.
Inrush Current Limiting:
Includes series inrush current limiting at USB power.
Cable Length/Connection Distance
: 5.0 meters maximum.
Driver:
No special drivers required. Uses the built-in USB Human Interface Device
(HID) drivers of the Windows Operating System (Windows XP or later versions only).
USB Connector:
5-pin, Mini USB B-type socket, Molex 67503-1020.
PIN
DEFINITION
1
+5V Power (Includes Inrush Current Limiting)
2
Differential Data (+)
3
Differential Data (-)
4
NC – Not Connected
5
1
Power Ground (Connects to Signal Ground via ferrite bead)
SHLD
1
Signal Ground (Connects directly to Signal Ground)
1
Note:
Most Host Personal Computers (except battery powered laptops) will connect
earth ground to the USB shield and signal ground.
!