IOtech 652u and 655u User’s Manual
878091
Block Diagram 2-3
General Comments
The following short descriptions are provided to supplement the block diagrams presented on pages 2-1 and 2-2.
For additional information refer to Chapter 3,
Connectors, Indicators, and Cables
.
USB2.0
The IOtech 652u and 655u transfer acquired data to the PC via a USB2.0 connection. It is important
to note that USB ports and USB hubs cannot supply sufficient power to 652u or 655u.
Power
Power (6 to 16VDC at 400mA) is typically supplied by a TR-2U power adapter connected to the
External Power Jack. An equivalent source of DC power can be used in place of a TR-2U.
LEDs
Active
The Active LED is on whenever active communication is taking place between the
652u [or 655u] and the host PC. Note that the Active LED will be on solid during a data
acquisition.
Power
The “Power” LED blinks during device detection and initialization; then remains on solid
as long as the module has power. If there is insufficient power the LED will go off.
Digital
I/O
To make use of the Digital I/O feature the 652u [or 655u] must be operating with eZ-TOMAS or
eZ-NDT. The 8-bits of digital I/O are provided via a rear panel DB9 connector. Each bit is
programmable as input or output.
BNCs
Up to ten BNC connectors, designated as Channels 1 through 10, can be used to connect analog input
signals to the 652u [or 655u]. The BNC center-conductor is the signal HI and the BNC shell is the
signal LO.
5 Channel
TC / RTD
Removable
Connector
(
Applies to the 655u only
) The 5 channel TC / RTD removable connector connects to the rear panel of
the 655u. The connector can be used to connect up to five temperature measurement channels. Each
channel can use a thermocouple or an RTD.
Chapter 3 includes a
connector pinout and wiring diagrams
•
Thermocouple
for the following:
•
TD 4-wire
•
RTD 3-wire
•
RTD-2 wire
Note
: Earth grounds are available for shielded sensors.
