Campbell Scientific SDM-CD8S User Manual
SDM-CD8S 8 Channel Solid
State DC Control Module
Revision: 4/12
Copyright © 2009-2012
Campbell Scientific, Inc.
Warranty
“PRODUCTS MANUFACTURED BY CAMPBELL SCIENTIFIC, INC. are
warranted by Campbell Scientific, Inc. (“Campbell”) to be free from defects in
materials and workmanship under normal use and service for twelve (12)
months from date of shipment unless otherwise specified in the corresponding
Campbell pricelist or product manual. Products not manufactured, but that are
re-sold by Campbell, are warranted only to the limits extended by the original
manufacturer. Batteries, fine-wire thermocouples, desiccant, and other
consumables have no warranty. Campbell's obligation under this warranty is
limited to repairing or replacing (at Campbell's option) defective products,
which shall be the sole and exclusive remedy under this warranty. The
customer shall assume all costs of removing, reinstalling, and shipping
defective products to Campbell. Campbell will return such products by surface
carrier prepaid within the continental United States of America. To all other
locations, Campbell will return such products best way CIP (Port of Entry)
INCOTERM® 2010, prepaid. This warranty shall not apply to any products
which have been subjected to modification, misuse, neglect, improper service,
accidents of nature, or shipping damage. This warranty is in lieu of all other
warranties, expressed or implied. The warranty for installation services
performed by Campbell such as programming to customer specifications,
electrical connections to products manufactured by Campbell, and product
specific training, is part of Campbell’s product warranty. CAMPBELL
EXPRESSLY DISCLAIMS AND EXCLUDES ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. Campbell is not liable for any special, indirect,
incidental, and/or consequential damages.”
Assistance
Products may not be returned without prior authorization. The following
contact information is for US and international customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company serves
your country.
To obtain a Returned Materials Authorization (RMA), contact CAMPBELL
SCIENTIFIC, INC., phone (435) 227-9000. After an applications engineer
determines the nature of the problem, an RMA number will be issued. Please
write this number clearly on the outside of the shipping container. Campbell
Scientific's shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
For all returns, the customer must fill out a "Statement of Product Cleanliness
and Decontamination" form and comply with the requirements specified in it.
The form is available from our web site at www.campbellsci.com/repair. A
completed form must be either emailed to repair@campbellsci.com or faxed to
(435) 227-9106. Campbell Scientific is unable to process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer's expense. Campbell Scientific reserves the right to refuse service on
products that were exposed to contaminants that may cause health or safety
concerns for our employees.
SDM-CD8S Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.
1. Function........................................................................1
2. Specifications ..............................................................2
3. Power Considerations................................................. 2
4. Installation....................................................................3
4.1 Wiring.......................................................................................................3
4.1.1 SDM-CD8S Power and Control Connections.................................3
4.1.2 Controlled Device Connections ......................................................4
5. Address Selection Switch........................................... 5
6. Datalogger Instructions ..............................................6
6.1 CRBasic Dataloggers (CR800, CR850, CR1000, CR3000, CR5000,
CR9000(X)) ...........................................................................................6
6.2 Datalogger Instructions 104 (CR10/10X, CR23X, 21X, CR7) and 29
(older CR7s)...........................................................................................7
7. Theory of Operation ....................................................8
8. Program Examples ......................................................8
8.1 Control Temperature and Fans – CR1000 ................................................8
8.2 Control Temperature and Fans – CR10X ...............................................11
8.3 Control Gas Sampling Based on Time – CR1000 ..................................15
8.3.1 Terminology..................................................................................15
8.3.2 Data Tables ...................................................................................16
8.3.3 Initialization Section (between BeginProg and Scan)...................16
8.4 Control Gas Sampling with Timing in Measurement Task – CR1000 ...19
8.4.1 The Purpose of this Example ........................................................19
8.4.2 Pipeline vs Sequential ...................................................................19
8.4.3 TimedControl Instruction..............................................................20
Figures
1. SDM-CD8S face panel ...............................................................................1
2. Connection block diagrams ........................................................................4
3. Typical wiring application..........................................................................5
i
SDM-CD8S Table of Contents
Tables
1. Datalogger to SDM-CD8S Connections .................................................... 4
2. Switch Position and Addresses .................................................................. 5
ii
SDM-CD8S 8 Channel Solid State DC Control Module
1. Function
FIGURE 1. SDM-CD8S face panel
The SDM-CD8S has 8 DC voltage outputs and returns that can be switched on
and off manually or under datalogger control. The “switch” is in the power
return. The power Input (6-26 VDC) powers both the outputs and the SDMCD8 logic. LEDs allow a visual indicator of active outputs.
The outputs can be controlled by a datalogger or controlled manually with an
override switch and individual rocker switches for each of the outputs.
When the manual control switch is in the ON position, outputs are controlled
by the position of the individual rocker switches. In the OFF position the state
of the relays is controlled by the SDM commands from the datalogger.
1
SDM-CD8S 8 Channel Solid State DC Control Module
The SDM-CD8S is a synchronously addressed datalogger peripheral.
Datalogger control ports 1, 2, and 3 are used to address the SDM-CD8S, then
clock out the desired state of each of the 8 control ports. Up to 15 SDMCD8Ss may be addressed, making it possible to control a maximum of 120
ports from the datalogger’s first three control ports. The SDMCD16AC
instruction is used to control the SDM-CD8S in CRBasic dataloggers. In
Edlog dataloggers that support SDM-CD16 devices, I/O Instruction 104 is
used (some old CR7s may use Instruction 29).
In addition to SDM control, the SDM-CD8S has the option of being operated
in a shift register mode. To operate in the shift register mode the address
switch is set to 15.
NOTE
Ensure that the datalogger contains the appropriate instruction
and test your datalogger program before going in the field.
2. Specifications
Compatible dataloggers: CR9000(X), CR5000, CR3000,
Supply voltage: 8 to 26 VDC
Logic current drain at 12 VDC: 15 mA quiescent;
Maximum cable length: 20 ft total to all SDM devices.
Toggle switch: MANUAL, AUTO
Maximum current per channel: 1 Amps
Maximum current all channels total: 6 Amps
Actuation/release times: 8 μs/200 μs
CR1000, CR850, CR800, CR23X,
CR10(X), 21X, and CR7.
2.5 mA per active LED (manual or
auto)
Consult CSI if longer lengths are
necessary.
Individual dip switches for manual
Operating temperature: -40° to 70°C
Dimensions: 11.1 x 8.6 x 2.4 cm (4.4 x 3.4 x 0.9 in.)
3. Power Considerations
The SDM-CD8S power requirements may be large compared to most
Campbell Scientific products. For most applications, an external power supply
(see Figure 2) is recommended to power the SDM-CD8S.
For some applications, it may be convenient to use the datalogger supply to
power the SDM-CD8S (see Figure 2). For long-term applications, the lead
acid power supply available with our dataloggers should be used, allowing the
batteries to be float charged. It is not recommended that the datalogger
alkaline supply be used to power the SDM-CD8S for long-term applications.
2
4. Installation
CAUTION
SDM-CD8S 8 Channel Solid State DC Control Module
If the datalogger lead acid supply is used, the current available from the wall
charger limits the continuous output current.
If the 21X power supply is used to power the SDM-CD8S Load Power, all low
level analog measurements (thermocouples, pyranometers, thermopiles, etc.)
must be made differentially. This is a result of slight ground potentials created
along the 21X analog terminal strip when the 12 V supply is used to power
peripherals. This limitation reduces the number of available analog input
channels and may mandate an external supply for the SDM-CD8S.
• The SDM-CD8S must be installed in an enclosure that provides a
pollution degree 2 environment (normally, only nonconductive pollution.
However, a temporary conductivity caused by condensation may be
expected). All Campbell Scientific enclosures meet this requirement.
• Use copper conductors only.
Cables connecting the terminals of the datalogger and
SDM device should be kept as short as possible to
minimize the risk of corruption of the signals and damage
from induced surges. Where long cable runs (>3 m) are
unavoidable and the cables run outside, some extra
protection may be required for the SDM control terminals.
Please contact Campbell Scientific for further advice.
When connecting wires to the SDM signal terminals,
please ensure they are at ground potential before making
the connection, e.g. by touching them to the earth terminal.
For datalogger connections, see Table 1.
Multiple SDM-CD8Ss may be wired in parallel by connecting the datalogger
side of one SDM-CD8S to the next. In most installations the total length of the
cables connecting the SDM-CD8S and other SDM peripherals should not
exceed 20 feet.
Total cable lengths in excess of 20 feet may adversely influence
communication performance. (For CR7 dataloggers, the total cable length
should not exceed 600 feet.)
4.1 Wiring
4.1.1 SDM-CD8S Power and Control Connections
Refer to Figure 2 and Table 1 for SDM-CD8S operating power and control
connections to the datalogger.
3
SDM-CD8S 8 Channel Solid State DC Control Module
EXTERNAL
8 TO 26 VDC
+ —
GND
SDM-CD8S
Connection to External Supply
SDM-CD8S
Connection to Datalogger Supply
FIGURE 2. Connection block diagrams
TABLE 1. Datalogger to SDM-CD8S Connections
SDM-CD8S Datalogger Function
PWR 12 V on datalogger or
8 to 26 V external supply
Logic Gnd Gnd Common ground
C1 C1 (Control Port 1) Data
C2 C2 (Control Port 2) Clock
C3 C3 (Control Port 3) Enable
C1
C2
C3
GND
12 V
C1
C2
C3
Power
DATALOGGER
DATALOGGER
4
4.1.2 Controlled Device Connections
In most applications, the SDM-CD8S acts as a switch (controllable break) in
the ground return of the circuit powering the controlled device. Figure 3
shows an example.
Loading...