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SDM-CD16D 16 Channel Digital Control
Port Expansion Module
The SDM-CD16D (see Figure 1) is a synchronously addressed peripheral. It has 16 control
ports and is compatible with Campbell Scientific’s CR10/10X, CR23X, CR7 and 21X
dataloggers.
Figure 1 SDM-CD16D
1. Introduction
The SDM-CD16D expands the digital output capability of Campbell Scientific
dataloggers. The outputs can be set to 0 or 5V by the datalogger. In addition to
being able to drive normal logic level inputs, when an output is set HI a ‘boost’
circuit allows it to source a current of up to 100mA, allowing direct control of low
voltage valves, relays etc.
The SDM-CD16D is a synchronously addressed datalogger peripheral. Datalogger
control ports 1, 2 and 3 are used to address the SDM-CD16D then clock out the
desired state of each of the 16 control ports. Up to sixteen SDM-CD16Ds may be
addressed, making it possible to control a maximum of 256 ports from the first
three datalogger control ports.
CR10/10X, CR23X, CR7 and 21X dataloggers use I/O Instruction
104 to control the SDM-CD16D.
Older dataloggers with pre-OS7.1 software may not have the
necessary instruction, or may use Instruction 29. Ensure that your
datalogger contains the appropriate instruction before using.
2. Control Specifications
2.1 General
Compatible dataloggers
:
CR10/10X, CR23X, CR7 and 21X
Operating voltage
:
12V DC nominal (9 to 18V)
Current drain at 12V DC
: 100µA typical (All ports HI, no load)
Total cable length:
6m (CR10/10X, CR23X, 21X), 180m (CR7)
NOTE
