Campbell Scientific SDM-IO16 16-Channel Input/Output Expansion Module - Manual (Page 21)

SDM-IO16 16 Channel Input/Output Expansion Module
Instruction 29 –used with older CR7s
Parameter Type Description
1 2 Reps (No. of modules sequentially addressed)
2 2 Device (2 = SDM-CD16/SDM-IO16)
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
Please note that these instructions use base 4 addressing. See the table with
Figure 5 to see the matching setting of the address switch on the SDM-IO16
that equates to any base 4 address.
The number of SDM-IO16s to be addressed is defined by the Reps
(repetitions) parameter. Each Rep sequentially addresses (00, 01, 02,...32, 33)
SDM-IO16s, starting with the address specified in parameter 2 (parameter 3
for Instruction 29).
For each repetition, the 16 ports of the addressed SDM-IO16 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-IO16 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-
IO16 are set according to input locations 33 to 48, and outputs 1 to 16 of the
second SDM-IO16 are set according to input locations 49 to 64.
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-CD16/IO16 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.
6.4 Command Codes for SDMIO16 Instruction and Instruction
188
The same command codes are used for all datalogger types that support the
SDM-IO16 instruction, therefore this section applies to both forms of
instruction.
There are approximately 100 command codes; the full list is tabulated in
Appendix B. The reason there are so many codes is that each type of action is
generally possible for either a single or block of ports of various sizes, as
discussed in section 6.1 above. A summary table of common command codes
is shown in Table 3, below. There are only a relatively small number of
different types of action that allows the commands to be grouped, as follows:
15