INFICON RQCM - Quartz Crystal Microbalance Research System - Manual (Page 87)

RQCM – RESEARCH QUARTZ CRYSTAL MICROBALANCE
DATA ACQUISITION CARD (OPTIONAL) 8-1
8 DATA ACQUISITION CARD (OPTIONAL)
The RQCM has one rear panel slot for the optional Data Acquisition Card. The card has three (3)
temperature inputs to accommodate an RTD, thermocouple and thermistor. There are also five (5)
scalable analog inputs for measuring and logging of DC voltages. Except for the thermocouple
input, which has its own connector, all other temperature inputs and analog inputs are on a D-
SUB 25 pin male connector. Figure 30 shows the connector pin configuration and Table 8-1
shows the pin signal assignments. Refer to the online help included in the RQCM software for
instructions on setting up and programming of these inputs.
Figure 30 DB25P Data Acquisition Rear Panel Connector
Pin Number Function
1, 2, 3 Voltage Input #1 (Input, Common, Shield)
4, 5, 6 Voltage Input #2 (Input, Common, Shield)
7, 8, 9 Voltage Input #3 (Input, Common, Shield)
10, 11, 12 Voltage Input #4 (Input, Common, Shield)
14, 15, 16 Voltage Input #5 (Input, Common, Shield)
17, 18, 19 Thermocouple Input (Hi, Lo, Shield)
20, 21, 22, 23, 24 RTD Input (Hi, Hi Sense, Lo Sense, Lo, Shield)
25 Voltage Reference
13 Not used
Table 8-1 DB25P Data Acquision Rear Panel Connector Pin Assignments
8.1 VOLTAGE INPUTS
Each of the five analog inputs can be configured as 0 to 5V, 0 to 10V, ±5V, or ±10V. The
unipolar positive inputs can be connected as unipolar negative inputs. The resolution of the data
is dependent on the range selection as shown in the table below.
Configuration Resolution
0 to 5V 0.1 mV
0 to 10V 0.2 mV
±
5V 0.2 mV
± 10V 0.5 mV
Table 8-2 Input Voltage Resolution
The voltage input pairs are labeled as Input and Common. The Input pin is the positive input and
the Common pin is the negative input. The common mode range is ±200V, so the Common pin
can be used to read unipolar negative voltages with the input pin as common. Each input also has
a Shield pin for shielded cable termination. Shielded, twisted pair cable is recommended for
connections longer than a foot.