You may find the following booklet, prepared by the FCC, helpful: How to Identify and Resolve Radio-TV Interference Problems. This book is available from the U.S. Government Printing Office, Washington, D. C. 20402, Stock No. 004-00-00345-4.
Teledyne Isco offers two serial outputs from 4200 series flow meters. There is a software-enabled output that is transmitted on the RAIN GAUGE connector. This signal also appears on the INTERROGATOR connector. This feature lets the flow meter transmit the most recent values for all currently enabled ports as ASCII text. You can select the baud rate and the frequency of transmission. You can then write a simple program to retrieve this data periodically, or you can do it interactively using a ter- minal program. This option (SERIAL OUTPUT) is discussed in detail in Section 2.
Teledyne Isco offers a 300 baud output on the RAIN GAUGE con- nector. This port provides ASCII level and flow rate data for remote transmission to any ASCII-compatible equipment. Every 15 seconds the flow meter transmits a line of data which includes level, units of level measurement, percentage of maximum flow rate, maximum flow rate, a total flow value, units of flow, sample number, bottle number, text, time, and date.
If you are using the flow meter with an Isco sampler, the data line also includes an indication of a sampling event.
You can transmit this data line to a computer, or to a locally-con- nected (within 250 feet) device capable of interpreting serial data, such as a video display terminal or a printer. The specifica- tions for this serial data output are as follows: 300 baud, 7 data bits, 2 stop bits, even parity. The printed (or displayed) line con- tains 110 characters and will appear similar to the following:
+01.409F 100.00% 2.500+0 CFS 0001533+0 CF 00 00 90 DEGREE V-NOTCH WEIR
000 0 90 04 04 02 31 48
The last two characters (not displayed) are a ‘CR' (carriage return) and a ‘LF' (line feed). The large gaps between some of the words indicate extra character spaces which are not used in this particular text, but which are available for use if needed.
Note
You cannot use both serial outputs at the same time. You must select one or the other.
The serial output is paralleled with the Interrogator Port and the Internal Modem. Use of either the Interrogator Port or the Internal Modem will cause non-standard data to be transmit- ted.
These outputs provide connection between a 4220 Flow Meter and non-Isco process-control equipment, such as chlorinators, or any other type of equipment that you can control with a 4-20 mil- liampere current loop. Analog outputs convert digital infor-
