Campbell SDM-CD16D User manual

SDM-CD16D
16 Channel Digital Control
Port Expansion Module
User Guide
Issued 15.6.99
Copyright 1999 Campbell Scientific Ltd.

Guarantee
This equipment is guaranteed against defects in materials, workmanship,
and software. This guarantee applies for twelve months from date of
delivery. We will repair or replace products which prove to be defective
during the guarantee period provided they are returned to us prepaid. The
guarantee will not apply to:
•Equipment which has been modified or altered in any way without the
written permission of Campbell Scientific
•Batteries
•Any product which has been subjected to misuse, neglect, acts of God
or damage in transit.
Campbell Scientific will return guaranteed equipment by surface carrier
prepaid. Campbell Scientific will not reimburse the claimant for costs
incurred in removing and/or reinstalling equipment. This guarantee and
the Company’s obligation thereunder is in lieu of all other guarantees,
expressed or implied, including those of suitability and fitness for a
particular purpose. Campbell Scientific is not liable for consequential
damage.
Please inform us before returning equipment and obtain a Repair Refer-
ence Number whether the repair is under guarantee or not. Please state the
faults as clearly as possible, and if the product is out of the guarantee
period it should be accompanied by a purchase order. Quotations for re-
pairs can be given on request.
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charges are greater than the cost of the repair.
Campbell Scientific Ltd,
Campbell Park, 80 Hathern Road,
Shepshed, Leicestershire, LE12 9RP, UK
Tel: [phone]
Fax: [phone]
Email: [email protected]
www.campbellsci.co.uk

Contents
1. Introduction...................................................................1
2. Control Specifications..................................................1
2.1 General................................................................................................1
2.2 Output Specifications...........................................................................2
3. Power Considerations..................................................2
4. Installation.....................................................................3
4.1 Controlled Device Connections............................................................4
5. Address Selection Switches........................................5
6. Datalogger Instructions 104 (CR10/10X, CR23X,
21X & newer CR7s) and 29 (older CR7s)...................6
7. Theory of Operation......................................................7
8. Program Example..........................................................7
Figures
1. SDM-CD16D.........................................................................................1
2. Equivalent Output Driver Circuit...........................................................2
3. Connection Block Diagrams...................................................................3
4. Use of Terminal Blocks..........................................................................5
5. Address Selection Switch.......................................................................6
Tables
1. Datalogger to SDM-CD16D Connections...............................................4
2. Switch Position and Address..................................................................5

1
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

SDM-CD16D 16 Channel Digital Control Port Expansion Module
2
2.2 Output Specifications
Output Voltage (no load): Output ON/HI, Nominal 5V (Minimum 4.5V)
Output OFF/LO, Nominal 0V (Maximum 0.1V)
Output Sink Current: Output will sink 8.6mA from a 5V source*
Output Source Current: Output will source 36mA @ 3V,
115mA short-circuited to ground*
Max. Output Current: 400mA at 50°C and 12V supply (see NOTE below)
(total all outputs)
The maximum current should be derated under the following
conditions:
50mA for every 10°C above 50°C and/or 50mA for every volt
above 12V.
Operating temp.: -25°C to +70°C standard
Size: 230mm wide x 100mm high x 24mm deep
Weight: 350g
EMC Status: Complies with EN55022-1:1998 and
EN50082-1:1998
* If more detailed output characteristics are required, experienced users should consult the
equivalent circuit diagrams shown in Figure 2, below.
Figure 2 Equivalent Output Driver Circuit
3. Power Considerations
The SDM-CD16D power requirements are large compared to most Campbell
Scientific products when driving significant loads. For many applications an
external power supply, as shown in Figure 3, is recommended to power the
SDM-CD16D.
For some applications it may be convenient to use the datalogger supply to power
the SDM-CD16D, as shown in Figure 3. For long-term applications, the lead-acid
power supply available with Campbell Scientific dataloggers should be used,
allowing the batteries to be float charged. Alkaline batteries are not recommended
for long term applications.
NOTE
0.6V Drop
Output
Output
580R
Output set ON/HI Output set OFF/LO
5
1
0
R
39
R
V
5V, 0Ω

User Guide
3
Connection with External Supply
Connection with Datalogger Supply
Figure 3 Connection Block Diagrams
If the 21X power supply is used to power the SDM-CD16D, all low
level analogue measurements (thermocouples, pyranometers,
thermopiles, etc.) must be made differentially.This is a result of slight
ground potentials created along the 21X analogue terminal strip when
the 12V supply is used to power peripherals. This limitation reduces
the number of available analogue input channels and may make an
external supply for the SDM-CD16D essential.
4. Installation
For correct operation the SDM-CD16D must be installed where there is no
risk of water ingress or condensation.
The order in which connections are made is critical.
Always
connect 12V first
, followed by ground, then the control ports.
For datalogger connections, see Table 1, below. Please refer to Figure 4 for details
of how to use the spring-loaded terminals.
NOTE
CAUTION
GND
EXTERNAL
9 TO 18V DC
+ –
SDM-CD16D DATALOGGER
12V C1
C2
C3
SDM-CD16D DATALOGGER
GND
12V
C1
C2
C3

SDM-CD16D 16 Channel Digital Control Port Expansion Module
4
Table 1 Datalogger to SDM-CD16D Connections
Connection Order SDM-CD16D Datalogger Function
First 12V 12V on datalogger or
external supply
Power
Second
C1
C2
C3
or G
C1 (Control Port 1)
C2 (Control Port 2)
C3 (Control Port 3)
Common Ground
Data
Clock
Enable
Multiple SDM-CD16Ds may be wired in parallel by connecting the datalogger
side of one SDM-CD16D to the next.
The transient protection of the SDM-CD16D relies on a low resistance path
to earth. Ensure that the ground return wire has as low a resistance as
possible. Where long cable runs are likely, or where lightning damage is a
possibility, the SDM-CD16D can be fitted with gas discharge tubes. Please
contact Campbell Scientific for details.
For CR10/10X, CR23X and 21X dataloggers, the total cable length
connecting SDM-CD16Ds to SDM-CD16Ds and the datalogger
should not exceed 6m. Total cable lengths in excess of 6m will
adversely affect communication performance. For CR7 dataloggers,
the total cable length can be up to 180m.
4.1 Controlled Device Connections
The SDM-CD16D uses spring-loaded terminal blocks, which provide quick,
vibration resistant, connections. The output terminals are labelled 1 to 16. A
common ground connector is provided between each pair of terminals
Use a screwdriver in either the top or front slot, as appropriate, to open the
terminal spring. Strip any insulation from the wire to give 7 to 9mm bare wire.
Push the wire into the opening, and, while holding it in position, withdraw the
screwdriver to release the spring. The wire will now be firmly held in place. See
Figure 4, below.
You cannot reliably insert more than one solid-core wire into one
terminal connector unless the wires are soldered or clamped
together. When inserting more than one stranded wire, twist the bare
ends together before insertion.
NOTE
NOTE

User Guide
5
Figure 4 Use of Terminal Blocks
5. Address Selection Switches
Each SDM-CD16D can have 1 of 16 addresses.The factory-set address is 00.
Table 2 shows switch position and the corresponding address. Figures 1 and
5 shows the position of the switch. Note that you will have to remove the
mounting bracket to gain access to this switch.
Table 2 Switch Position and Addresses
Switch Setting Base 4 Address
000
101
202
303
410
511
612
713
820
921
A22
B23
C30
D31
E32
F33
Use a screwdriver in appropriate slot
to release spring tension
Strip insulation
and insert wire

SDM-CD16D 16 Channel Digital Control Port Expansion Module
6
Figure 5 Address Selection Switch
6. Datalogger Instructions 104 (CR10/10X, CR23X, 21X,
CR7) and 29 (older CR7s)
Instruction 104 is used by the CR10/10X, CR23X, CR7 and 21X to control the
SDM-CD16D, and Instruction 29 is used by older CR7s.The Instruction
descriptions are shown below.
Instruction 104 – SDM-CD16D used with CR10/10X, CR23X, CR7
and 21X dataloggers
Parameter Type Description
1 2 Reps (No. of modules sequentially addressed)
2 2 Starting Address (base 4: 00..33)
3 4 Starting Input Location
Execution Time = 2ms per Rep for the CR10/10X and CR23X
3.5ms per Rep for the 21X and CR7
Instruction 29 – SDM-CD16D used with older CR7s
Parameter Type Description
1 2 Reps (No. of modules sequentially addressed)
2 2 Device (2 = SDM-CD16D)
3 2 Starting Address (base 4: 00..33)
4 2 Card (Excitation card No.)
5 4 Starting Input Location
Execution Time = 150ms to 190ms per Rep
The number of SDM-CD16Ds to be addressed is defined by the Reps (repetitions)
parameter. Each Rep sequentially addresses (00, 01, 02,...32, 33) SDM-CD16Ds,
starting with the address specified in parameter 2 (parameter 3 for Instruction 29).
For each repetition, the 16 ports of the addressed SDM-CD16D are set according
to 16 sequential input locations starting at the input location specified in
parameter 3 (parameter 5 for Instruction 29). Any non-zero value stored in an
input location activates (sets HI 5V) the associated SDM-CD16D port. A value of
zero (0) de-activates the port (sets LO 0V). For example, assuming two repetitions
and a starting input location of 33, outputs 1 to 16 of the first SDM-CD16D are set
according to input locations 33 to 48, and outputs 1 to 16 of the second
SDM-CD16D are set according to input locations 49 to 64.
Use a screwdriver to select address

User Guide
7
For older CR7s with Instruction 29, the Device (parameter 2) specifies what type
of synchronously addressed peripheral is to be addressed. The Device code for an
SDM-CD16D is 2.
For Instruction 29 only (older CR7s), the Card parameter (parameter 4) specifies
which 725 Excitation Card is being used for the control port signals. The Reps
parameter does not advance beyond the specified Card, requiring another
Instruction 29 for each 725 Excitation Card used.
7. Theory of Operation
On power-up, all SDM-CD16D outputs are off /LO.
The SDM-CD16D is a synchronously addressed peripheral. C2 and C3, driven
high by the datalogger, initiate a cycle. While holding C3 high, the datalogger
drives C2 as a clock line and C1 as a serial data line. The datalogger shifts out a
data bit on C1 (LSB first) on the falling edge of the C2 clock. The SDM-CD16D
shifts in the C1 data bit on the rising edge of the C2 clock.
The first eight bits clocked out represent the SDM-CD16D address. If the address
matches the SDM-CD16D’s address, the SDM-CD16D is enabled. If enabled, the
next 16 bits are shifted into the SDM-CD16D, each bit controlling one port, the
first of which controls output 1.
When the 16 control bits are clocked in, C2 is held high while C3 is pulsed low
then high to latch the control bits. The datalogger then lowers both C3 and C2 to
complete the cycle.
8. Program Example
The example is written for the CR10/10X Measurement and Control Module. The
program concepts presented are the same for the CR23X, 21X and CR7
dataloggers with minor changes in the program code.
In this example, the SDM-CD16D is used to control the temperature between 23°C
and 28°C in each of five greenhouses. In each greenhouse the SDM-CD16D
controls a heating unit, a refrigerating unit and an air mixing fan according to the
following conditions:
Heating unit:
Activate when temperature <23.5°C.
Deactivate when temperature >25.5°C.
Cooling unit:
Activate when temperature >27.5°C.
Deactivate when temperature <24.5°C.
Mixing fan:
Activate whenever the heating or cooling units are activated.
Activate for 5 minutes out of every 15 minutes.
The program assumes that the temperature measurements have been made, and
that the average temperature for each greenhouse is computed and stored in input
locations 1 to 5. For further information on loops and input location indexing,
please refer to your datalogger manual.
Input location assignments are as follows:
Input Input
Location Location Label Description
1..5 Temp #1..#5 Avg. temp. greenhouse 1..5

SDM-CD16D 16 Channel Digital Control Port Expansion Module
8
10..14 Heat #1..#5 Heater control, greenhouse 1..5
SDM-CD16D Port 1..5
15..19 Cool #1..#5 Cooler control, greenhouse 1..5
SDM-CD16D Port 6..10
20..24 Fan #1..#5 Fan control, greenhouse 1..5
SDM-CD16D Port 11..15
;{CR10X}
;
*Table 1 Program
01: 5 Execution Interval (seconds)
1: Beginning of Loop (P87) Master loop: end
1: 0 Delay loop at step 30
2: 5 Loop Count
Start heater control logic
2: If (X<=>F) (P89) if temperature is below
1: 1 -- X Loc [ Temp_1 ] heater threshold
2: 4 <
3: 23.5 F
4: 30 Then Do then
3: Z=F (P30) put a ‘1’ into heater control
1: 1 F location
2: 0 Exponent of 10
3: 10 -- Z Loc [ Heat_1 ]
4: End (P95) end ‘then do’
5: If (X<=>F) (P89) if the heater is on (heater
1: 10 -- X Loc [ Heat_1 ] control location <>0)
2: 2 <>
3: 0 F
4: 30 Then Do then
6: If (X<=>F) (P89) check upper threshold
1: 1 -- X Loc [ Temp_1 ] to see if heater should
2: 3 >= be turned off
3: 25.5 F
4: 30 Then Do
7: Z=F (P30) if heater should be turned
1: 0 F off, enter a ‘0’ into
2: 0 Exponent of 10 heater control location
3: 10 -- Z Loc [ Heat_1 ]
8: End (P95) end ‘then do’
9: Else (P94) else, if the heater is off
10: Z=F (P30) enter a ‘0’ into heater
1: 0 F control location
2: 0 Exponent of 10
3: 10 -- Z Loc [ Heat_1 ]
11: End (P95) end ‘then do/else’

User Guide
9
End heater control logic
Start cooler control logic
12: If (X<=>F) (P89) if ‘cooler on’ threshold
1: 1 -- X Loc [ Temp_1 ] is exceeded
2: 3 >=
3: 27.5 F
4: 30 Then Do then
13: Z=F (P30) put a ‘1’ into cooler
1: 1 F control location
2: 0 Exponent of 10
3: 15 -- Z Loc [ Cool_1 ]
14: End (P95) end ‘then do’
15: If (X<=>F) (P89) if cooler is on (cooler
1: 15 -- X Loc [ Cool_1 ] control location <>0)
2: 2 <>
3: 0 F
4: 30 Then Do then
16: If (X<=>F) (P89) check lower threshold to
1: 1 -- X Loc [ Temp_1 ] see if cooler should be
2: 4 < turned off
3: 24.5 F
4: 30 Then Do
17: Z=F (P30) if cooler should be turned off
1: 0 F put a ‘0’ into cooler control
2: 0 Exponent of 1 location
3: 15 -- Z Loc [ Cool_1 ]
18: End (P95) end ‘then do’
19: Else (P94) else, if cooler is off
20: Z=F (P30) put a ‘0’ into cooler
1: 0 F control location
2: 0 Exponent of 10
3: 15 -- Z Loc [ Cool_1 ]
21: End (P95) end ‘then do/else’
End cooler control logic
Start fan control logic based on heater/cooler
22: If (X<=>F) (P89) if heater is on
1: 10 -- X Loc [ Heat_1 ]
2: 2 <>
3: 0 F
4: 11 Set Flag 1 High set flag 1
23: If (X<=>F) (P89) if cooler is on
1: 15 -- X Loc [ Cool_1 ]
2: 2 <>
3: 0 F
4: 11 Set Flag 1 High set flag 1
24: If Flag/Port (P91) if flag 1 is set
1: 11 Do if Flag 1 is High
2: 30 Then Do then
25: Z=F (P30) put a ‘1’ into fan control
1: 1 F location

SDM-CD16D 16 Channel Digital Control Port Expansion Module
10
2: 0 Exponent of 10
3: 20 -- Z Loc [ Fan_1 ]
26: Else (P94) else, if flag 1 is reset
27: Z=F (P30) put a ‘0’ into fan control
1: 0 F location
2: 0 Exponent of 10
3: 20 -- Z Loc [ Fan_1 ]
28: End (P95) end ‘then do/else’
29: Do (P86) reset flag 1
1: 21 Set Flag 1 Low
30: End (P95) end master loop
End fan control logic based on heater/cooler
Start fan control logic based on time
31: If time is (P92) if 5 minutes remain
1: 10 Minutes (Seconds --) into a out of 15 minute
2: 15 Interval (same units as above) interval
3: 12 Set Flag 2 High set flag 2
32: If Flag/Port (P91) if flag 2 is set
1: 12 Do if Flag 2 is High
2: 30 Then Do then
33: Beginning of Loop (P87) start fan loop
1: 0 Delay
2: 5 Loop Count
34: Z=F (P30) put a ‘1’ into fan control
1: 1 F location
2: 0 Exponent of 10
3: 20 -- Z Loc [ Fan_1 ]
35: End (P95) end fan loop
36: End (P95) end’ then do’
37: If time is (P92) reset flag 2 at the
1: 0 Minutes (Seconds --) into a end of the 15 minutes
2: 15 Interval (same units as above)
3: 22 Set Flag 2 Low
End fan control logic based on time
Input locations 10 to 24 are now loaded with a ‘1’ or ‘0’ to set ports on the SDM-CD16D
38: SDM-CD16 / SDM-CD16D (P104) send instructions to the
1: 1 Reps SDM-CD16D with address 00
2: 00 Address
3: 10 Loc [ Heat_1 ]
*Table 2 Program
02: 0.0000 Execution Interval (seconds)
*Table 3 Subroutines
End Program
-Input Locations-
1 Temp_1 7 4 0
2 Temp_2 10 0 0
3 Temp_3 10 0 0

User Guide
11
4 Temp_4 10 0 0
5 Temp_5 18 0 0
6 _________ 0 0 0
7 _________ 0 0 0
8 _________ 0 0 0
9 _________ 0 0 0
10 Heat_1 7 3 3
11 Heat_2 11 1 0
12 Heat_3 11 1 0
13 Heat_4 11 1 0
14 Heat_5 19 1 0
15 Cool_1 7 3 3
16 Cool_2 11 1 0
17 Cool_3 11 1 0
18 Cool_4 11 1 0
19 Cool_5 19 1 0
20 Fan_1 7 1 3
21 Fan_2 11 1 0
22 Fan_3 11 1 0
23 Fan_4 11 1 0
24 Fan_5 19 1 0
25 _________ 1 1 0
26 _________ 0 0 0
27 _________ 0 0 0
28 _________ 0 0 0
29 _________ 0 0 0