1 | External components
18200-00 Operating Manual
External components
The 18200-00 has the following external components, as shown in Figure 3-1.
USB connector
LED
Screw terminal banks (2)
Screw terminals
Pins 1-20
LED
Functional Details
Screw terminals
Pins 21-40
USB connector/cable
Figure 3-1. 18200-00 external components
USB connector
The USB connector is on the right side of the 18200-00 housing. This connector provides +5V power and communication. The voltage supplied through the USB connector is system-dependent, and may be less than
5V. No external power supply is required.
LED
The LED on the front of the housing indicates the communication status of the 18200-00. It uses up to 5 mA of
current and cannot be disabled. Table 3-1 defines the function of the 18200-00 LED.
Table 3-1. LED illumination
When the LED is… It indicates…
Steady green
Blinks continuously
Blinks three times
Blinks at a slow rate
The 18200-00 is connected to a computer or external USB hub.
Data is being transferred.
Initial communication is established between the 18200-00 and the computer.
The analog input is configured for external trigger. The LED stops blinking and illuminates steady green when the trigger is received.
Screw terminal wiring
The 18200-00 has two rows of screw terminals—one row on the top edge of the housing, and one row on the
bottom edge. Each row has 20 connections. Pin numbers are identified in Figure 3-2.
12
18200-00 Operating Manual Functional Details
Figure 3-2. 18200-00 Screw terminal pin numbers
Screw terminal – pins 1-20
The screw terminals on the top edge of the 18200-00 (pins 1 to 20) provide the following connections:
Eight analog input connections (
CH0 IN
to
CH7 IN
)
Two analog output connections (
D/A OUT 0
to
D/A OUT 1
)
One external trigger source (
TRIG_IN
)
One external event counter connection (
CTR
)
Seven GND connections (
GND
)
One calibration terminal (
CAL
)
Screw terminal – pins 21-40
The screw terminals on the bottom edge of the (pins 21 to 40) provide the following connections:
16 digital I/O connections (
PortA0
to
Port A7
, and
Port B0
to
Port B7
)
One power connection (
PC+5 V
)
Three ground connections (
GND
)
Main connector and pin out
Connector type
Wire gauge range
Screw terminal
16 AWG to 30 AWG
13
18200-00 Operating Manual
11 10 9G
Functional Details
4-channel differential mode pin out
8-channel single-ended mode pin out
Analog input terminals (CH0 IN - CH7 IN)
You can connect up to eight analog input connections to the screw terminal containing pins 1 to 20 (
CH0 IN
through
CH7 IN
). Refer to the pinout diagrams
above for the location of these pins.
You can configure the analog input channels as eight single-ended channels or four differential channels. When configured for differential mode, each analog input has 12-bit resolution. When configured for single-ended mode, each analog input has 11-bit resolution, due to restrictions imposed by the A/D converter.
Single-ended configuration
When all of the analog input channels are configured for single-ended input mode, eight analog channels are available. The input signal is referenced to signal ground (GND), and delivered through two wires:
The wire carrying the signal to be measured connects to CH# IN.
The second wire connects to GND.
3-3 illustrates a typical single-ended measurement connection.
Figure 3-3. Single-ended measurement connection
14
18200-00 Operating Manual Functional Details
Single-ended measurements using differential channels
To perform a single-ended measurement using differential channels, connect the signal to "CH
n
IN HI" input, and ground the associated "CH
n
IN LO" input.
Differential configuration
When all of the analog input channels are configured for differential input mode, four analog channels are available. In differential mode, the input signal is measured with respect to the low input.
The input signal is delivered through three wires:
The wire carrying the signal to be measured connects to CH0 IN HI, CH1 IN HI, CH2 IN HI, or
CH3 IN HI.
The wire carrying the reference signal connects to CH0 IN LO, CH1 IN LO, CH2 IN LO, or CH3 IN LO.
The third wire connects to GND.
A low-noise precision programmable gain amplifier (PGA) is available on differential channels to provide gains of up to 20 and a dynamic range of up to 12-bits. Differential mode input voltage ranges are ±20 V, ±10 V,
±5 V, ±4 V, ±2.5 V, ±2.0 V, 1.25 V, and ±1.0 V.
In differential mode, the following two requirements must be met for linear operation:
Any analog input must remain in the − 10V to +20V range with respect to ground at all times.
The maximum differential voltage on any given analog input pair must remain within the selected voltage range.
The input [
common
-
mode voltage
+
signal
] of the differential channel must be in the
− 10 V to +20 V range in order to yield a useful result. For example, you input a 4 V pp sine wave to CHHI, and apply the same sine wave 180° out of phase to CHLO. The common mode voltage is 0 V. The differential input voltage swings from 4 V
-
(-4 V) = 8 V to -4 V
-
4 V = -8V. Both inputs satisfy the -10 V to +20 V input range
requirement, and the differential voltage is suited for the ±10 V input range (see Figure 3-4).
+4V
Measured Signal
CHHI
0V
-4V
8V Differential
+/-8V
+4V
CHLO
-4V
Figure 3-4. Differential Voltage Example: Common Mode Voltage of 0 V
If you increase the common mode voltage to 11 V, the differential remains at ±8 V. Although the [
common
-
mode voltage
+
signal
] on each input now has a range of +7 V to +15 V, both inputs still satisfy the -10 V to
+20 V input requirement (see Figure 3-5).
15
18200-00 Operating Manual
CHHI
+15V
+11V
Measured Signal
Functional Details
8V Differential
+/-8V
CHLO
+11V
+7V
Figure 3-5. Differential Voltage Example: Common Mode Voltage of 11V
If you decrease the common-mode voltage to -7 V, the differential stays at ±8 V. However, the solution now violates the input range condition of -10 V to +20 V. The voltage on each analog input now swings from -3V to
CHHI
-3V
-7V
3V
-11V
Measured Signal
8V Differential
+/-7V
CHLO
-3V
-7V
-11V
Figure 3-6. Differential Voltage Example: Common Mode Voltage of -7 V
Since the analog inputs are restricted to a − 10 V to +20 V signal swing with respect to ground, all ranges
except
±20V can realize a linear output for any differential signal with zero common mode voltage and full scale signal inputs. The ±20 V range is the exception. You cannot put − 20 V on CHHI and 0 V on CHLO since this violates the input range criteria.
Table 3-2 shows some possible inputs and the expected results.
Table 3-2. Sample Inputs and Differential Results
CHHI CHLO Result
-20 V
-15 V
-10 V
-10 V
0 V
0 V
+10 V
+10 V
+15 V
+20 V
0 V
+5 V
0 V
+10 V
+10 V
+20 V
-10 V
0 V
-5 V
0
Invalid
Invalid
-10 V
-20 V
-10 V
-20 V
+20 V
+10 V
+20 V
+20 V
For more information on analog signal connections
For more information on single-ended and differential inputs, refer to the
Guide to Signal Connections
(this document is available on our web site at www.coleparmer.com/catalog/MoreInfo/CPsignals.pdf
.)
16
18200-00 Operating Manual Functional Details
Digital I/O terminals (Port A0 to A7, and Port B0 to B7)
You can connect up to 16 digital I/O lines to the screw terminal containing pins 21 to 40 (
Port A0
to
Port A7
, and
Port B0
to
Port B7
.) Refer to the pinout diagrams
on page 14 for the location of these pins. You can
configure each digital port for either input or output.
When you configure the digital bits for input, you can use the digital I/O terminals to detect the state of any
set to the +5 V input, Port A0 reads
TRUE
(1). If you move the switch to GND, Port A0 reads
FALSE
.
Figure 3-7. Digital connection Port A0 detecting the state of a switch
Port A0
+GND +5V
Figure 3-8. Schematic showing switch detection by digital channel Port A0
For more information on digital signal connections
For more information on digital signal connections and digital I/O techniques, refer to the
Guide to Signal
Connections
(available on our web site at www.coleparmer.com/catalog/MoreInfo/CPsignals.pdf
.)
Power terminals
The
PC +5 V
connection (pin 30) is on the bottom screw terminal of the 18200-00. Refer to the pinout diagrams
terminal is a 5 volt output that is supplied by the host computer.
Caution!
The +5V terminal is an output. Do not connect to an external power supply or you may damage the 18200-00 and possibly the computer.
The maximum total output current that can be drawn from all 18200-00 connections (power, analog and digital outputs) is 500 mA. This maximum applies to most personal computers and self-powered USB hubs.
Bus-powered hubs and notebook computers may limit the maximum available output current to 100 mA.
Just connecting the 18200-00 to your computer draws 20 mA of current from the USB +5 V supply. Once you start running applications with the 18200-00, each DIO bit can draw up to 2.5 mA, and each analog output can
17
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project