Campbell Hausfeld SM4M - Manual (Page 19)

3-1
Section 3. The Printer Enable Method of
Data Storage
Data from the 21X and CR7 with PROMs older than the OSX and OS7 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.
If the PE line is high when power is applied, the SM will not
store data until the next time PE goes high. Also, if power to
the SM 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 *4 Mode is not recommended.
For large volumes of data two SMs 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 Output
Processing Instructions in the program table. Consult the datalogger instruction
manual for details about using Instruction 96. Do not use both the *4 Mode and
Instruction 96 to activate a device in a datalogger program.
Instruction: 96
Parameter: 01:22
CAUTION