Teledyne 4220 - Manual (Page 112)

4220 Flow Meter
Section 5 Options and Accessories
5-4
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
P r i n t i n g O f f i c e , Wa s h i n g t o n , D. C. 2 0 4 0 2 , S t o c k N o .
004-00-00345-4.
5.2 Connection to
External Serial Device
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.
5.3 4-20 mA Analog
Outputs: External and
Internal
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-