Справочник Пользователя для Manfrotto 203

Скачать
Страница из 20
201/203 Series 
Page 6 of 20 
1.3.  Optional 4-20 mA Current Output 
An option to the standard 0-5 VDC output is the 4-20 mA current output that is proportional to 
flow.  The 4 - 20 mA signal is produced from the 0 - 5 VDC output of the flow meter.  The current 
loop output is useful for remote applications where pickup noise could substantially affect the 
stability of the voltage output.   
The current loop signal replaces the voltage output on pin 6 of the “D” connector.  The current loop 
may be returned to either the power supply ground or the -15 VDC connection on the power 
supply.  If the current loop is returned to the power supply ground, the load must be between 0 and 
600 ohm.  If it is returned to the -15VDC, the load must be between 600 and 1200 ohm.  Failure to 
meet these conditions will cause failure of the loop transmitter. 
The 4-20 mA I/O option can accept a current input.  The 0-5 VDC command signal on pin 14 can 
be replaced by a 4-20mA command signal.  The loop presets an impedance of 75 ohms and is 
returned to the power supply through the valve common. 
1.4. Other 
Accessories 
1.4.1. 
Totalizer (TR-1J)   
The Hastings Flow Totalizer integrates the 0-5 VDC signal generated by the flow meter to give a 
total flow reading.  Count rates from 0 to 999 counts per minute are selectable by internal setting. 
1.4.2. 
Hastings Model 40/200/400 Power Supply   
Hastings power supplies are available in either two or four channel versions.  They convert 115 or 
230VAC to the ±15 VDC required to operate the flow meter.  Interface terminals for the ±15 VDC 
input and the 0-5 VDC linear output signal are located on the rear of the panel.  Also, a cable can be 
supplied with the power supply that provides the +15 VDC on pin 11 of a 15-pin “D” connector 
and the 0 - 5VDC output measurement on pin 6.  Pins 5, 7 and 12 are common, and pin 7 is chassis 
ground.  Throughout this manual, when reference is made to a power supply, it is assumed the 
customer is using a Hastings Model 200/400/40 supply.  Hastings power supplies do not meet CE 
standards at this time.