CR10X Instruction Manual
OV-4
Analogue Inputs
The terminals labelled 1H to 6L are analogue inputs. These numbers refer to the
high and low inputs to the differential channels 1 to 6. In a differential meas-
urement, the voltage on the H input is measured with respect to the voltage on the
L input. When making single-ended measurements, either the H or L input may be
used as an independent channel to measure voltage with respect to the CR10X
analogue ground (AG). The single-ended channels are numbered sequentially
starting with 1H; e.g. the H and L sides of differential channel 1 are single-ended
channels 1 and 2; the H and L sides of differential channel 2 are single-ended
channels 3 and 4, and so on.
Single-ended channel numbers do not appear on older (silver) Wiring Panels.
Switched Excitation Outputs
The terminals labelled E1, E2 and E3 are precision, switched excitation outputs
used to supply programmable excitation voltages for resistive bridge measure-
ments. DC or AC excitation at voltages between -2500mV and +2500mV are user
programmable (see Section 9).
Pulse Inputs
The terminals labelled P1 and P2 are the pulse counter inputs. They are pro-
grammable for switch closure, high frequency pulse or low level AC (see
description of Instruction 3 in Section 9).
Digital I/O Ports
Terminals C1 to C8 are digital input/output ports. On power-up they are config-
ured as input ports, commonly used for reading the status of an external signal.
High and low conditions are: 3V < high < 5.5V; -0.5V < low < 0.8V.
Configured as outputs the ports allow on/off control of external devices. A port
can be set high (5V ± 0.1V), set low (<0.1V), toggled or pulsed (see Sections 3, 8
and 12).
Ports C6 to C8 can be configured as pulse counters for switch closures (see
Section 9 Instruction 3), or used to trigger subroutine execution (see Section 1).
Analogue Ground (AG)
The AG terminals are analogue grounds, used as the reference for single-ended
measurements and to provide a return path for excitation current.
12V, Power Ground (G) and Earth Terminals
The 12V and power ground (G) terminals are used to supply 12V DC power to the
datalogger. The complete terminal block can be unplugged from the datalogger to
simplify cable connection. The extra 12V and G terminals can be used to connect
other devices requiring 12V power.
The CR10X does not regulate the voltage to the extra 12V
terminals. The 12V terminals are connected directly to the 12V
power in terminal. Any voltage regulation must be done by the
power supply (see Section 14).
The G terminals are also used to tie cable shields to ground and to provide a ground
reference for pulse counters and binary inputs. The G terminals are directly
connected to the Earth terminal. For protection against transient voltage spikes,
power ground should be connected to a good earth ground (see Section 14).
NOTE
CAUTION
