Owner's manual

3-1
Section 3. The Printer Enable Method of
Data Storage
Data from the 21X and CR7 with PROMs older than the OSX and OX7 series PROMs (and
from the CR21 and DSP4) are stored in the Storage Module via the Printer Enable
Method; i.e., data on the TD line (pin 9) are stored while the PE line (pin 6) is high. The
Storage Module defaults to the Printer Enable Method each time it is powered up by 5V
DC applied to pin 1 of its 9-pin ‘D’ connector. Up to two Storage Modules can be
connected to the 21X or CR7 dataloggers at one time. If two are connected, one should be
set to Fill and Stop and the other configured as Ring Memory. Storage Module-to-Storage
Module dumps are not possible with the Printer Enable Method.
If the PE line is high when power is applied, the Storage
Module will not store data until the next time PE goes high.
Also, if power to the Storage Module is interrupted during
transmission, data stored since the last time PE went high
will be lost.
3.1 Baud Rates
In the Printer Enable Method, you must ensure that the baud rates of the
Storage Module and the datalogger are matched. The SM4M/SM16M will
only accept data at 9600 or 76800 baud. There is no user configuration for this
setting in the module as it automatically detects the speed of the data sent to it.
Baud rate errors (i.e., baud rate mismatches between the datalogger and the
Storage Module) cause the Storage Module to increment its error counter and
enter a low power standby state.
3.2 Storing Data from the 21X and CR7 (All Versions
Prior to OSX and OS7 Release)
Instruction 96 is the recommended method for the CR7 and the 21X with
Extended Software. The *4 Mode could also be used to transmit data in ASCII
format but Instruction 96 is more efficient as data is transferred in the most
compact binary format – therefore it is not recommended.
For large volumes of data two Storage Modules can be connected to the
datalogger. Use SMS to set one as Fill and Stop, and the other as Ring
Memory.
3.2.1 Instruction 96 — Output Under Program Control
Instruction 96, available in the CR7X and in the Extended Software PROMs
for the earlier versions of the 21X, is used to send Final Storage data to the
Storage Module under program control. Instruction 96 should follow the
CAUTION