AW Gear Meters EMO-500 - Manual (Page 36)

EMO-500
Operation and Programming Manual
35
The communications port does not discriminate any addresses. This means that any address can be
written to as well as read from. Writing to certain addresses changes the operation of the EMO-500
drastically. Caution is a must! Double check addresses and variables before writing to the EMO-500.
The bytes are always arranged such that the low byte (LSB) is first and the more significant bytes (MSB)
follow. In the EMO-500, the least significant byte is at the lower address. For example, if the data from
the totalizer is read as:
90D58901
the LSB is 90 and the MSB is 01.
The arrangement of these four bytes in the EMO-500 memory is:
Address = 05A0H 05A1H 05A2H 05A3H
Vaule = 90H D5H 89H 01H
Interpret the totalizer value as:
0189D590H = 25,810,320 (in decimal)
Address Information
When writing to the EMO-500, there are always two locations to be changed for a permanent entry into
the memory. This is because there are locations for data running currently in the RAM and for data that
is battery-backed. If the information has been written to the running locations alone, it is lost when the
EMO-500 is turned off.
Below is a QBASIC program that allows you to communicate with the EMO-500 by initiating serial port
#1 and prompting for read and write strings. The strings must use the OPTO 22 protocol format
described on page 32.
Warning!
Notice