Campbell SM4M, Instruction Manual

Page: 35 / 46

B-1
Appendix B. Telecommunications
Commands
The Storage Module telecommunications commands can be issued to an
Storage Module either via a direct SC532(A) connection to the Storage Module
or via a remote connection where the Storage Module is connected to a
datalogger.
Establishing communication between the Storage Module and a
computer/terminal is discussed in Section 5. The commands permit data
storage and retrieval, switch setting, status checks and other functions.
If you are making connections through a datalogger, make the connections
(Figure 5-4) and establish communications with the datalogger. Send the
command ‘XM,CR’ to the datalogger (where X is the Storage Module address
1...8). If the connections are correctly made and the Storage Module is
properly addressed, it will send back ‘CR, LF, %.’ If the attempt to establish
communications fails, the datalogger will return ‘*’.
The Storage Module is ready for a command when it sends its prompt,
‘<CR><LF> %’. The successful execution of a command is also indicated by
the Storage Module returning a ‘<CR><LF> %’. If just a ‘%’ is returned, the
command was in error. ‘
CTRL
-
S
’ (XOFF) temporarily halts Storage Module
responses to commands. ‘
CTRL
-
C
’ aborts the response.
The descriptions of some commands refer to the Storage Module pointers (see
Section 4). The Display Location Pointer (DLP) is used to display Storage
Module data. The Storage Reference Pointer (SRP) indicates the next
location to be written to in the Storage Module. The Dump Pointer is an
internal Storage Module pointer used for keeping track of the current start-of-
dump for Storage Module-to-Storage Module data dumps and for the data
retrieval options of the SMS program.
Storage Module telecommunications commands are similar to datalogger
telecommunications commands and consist of numbers and CAPITAL letters.
In the following list telecommunications commands are on the left and their
descriptions on the right.
A
Status Returns Version number, Switch settings, number of Programs stored, number
of good Data Memory blocks, number of Errors logged (max. = 255), number
of Available storage locations, number of locations Full, Storage Reference
Pointer, Display Location Pointer, Dump Pointer and Checksum (sum of all
transmitted ASCII characters since last %; wraps around at 8192 bytes).
The number of Errors logged is a count of bad characters received from the
datalogger and/or the number of times the module has reset itself as a result of
some unknown cause. Contact Campbell Scientific for advice if this counter
increments regularly. Unlike previous modules this counter does not increment
if corrupted characters are received in telecommunications mode.
Example: V1 S1400 P0 M64 E0 A2052258 F1 R2 L2 D2 C2226 is the
expected response to the A command after an SM4M has been reset.