Alarm Relays Programming; Trouble Alarms - Hach Sigma 950 Instrument Manual

8.4.2 Alarm Relays Programming

8.4.2.1 Trouble Alarms

Trouble Condition
Low Memory Battery
Low Slate Memory
Low Bubbler Pressure
Clogged Bubbler
U-Sonic Echo Loss (A pulse of
sound was sent but no echo was
received back)
Transducer Ringing
U-Sonic Failure
RS485 Timed Out
Pin
A
B
C
D
E
F
Rating
Form C relays are rated for 10 amps at 120 V ac or 5 amps at 240 V ac resistive load
min. Normally open and normally closed contacts are available.
Cable Required
Alarm Relay Cable Assembly, 25 ft (7.6 m), 6-pin connector on one end, tinned wire leads
on the other end (P/N 2705).
Alarms can be programmed to activate based on certain conditions (low battery, low
memory, etc.). Refer to 950 Flow Meter Advanced Options on page
tripped, an action is initiated (report via modem, dial a pager, or set a relay). Two types of
alarms are trouble and set point alarms.
Trouble Alarms initiate an action when a trouble condition occurs. For example, a relay
may close when the memory is full.
1. From the Main Menu, select
2. Enable one of the trouble conditions.
3. Select an action to occur when the alarm is activated.
Condition and its cause.
Table 29 Trouble Alarms
Cause
Internal memory battery voltage is too low. Change batteries.
Free slate memory is less than 20%
Bubbler system not developing sufficient air pressure. (Inspect air pump, reservoir, and
associated tubing assemblies for problem.)
Bubbler line obstructed or submerged below ten feet.
The echo has been temporarily deflected by a change in site conditions such as floating
debris or foam in the channel, wind, etc.
Transducer is operating within the deadband.
Transducer not plugged in. Cable damaged. Transducer thermal sensor damaged.
Problem with communications between the flow meter and a remote ultrasonic sensor.
May indicate open thermal sensor.
Table 28 Relay 3 & 4 Connector Pin Assignments
Signal Description
relay #3 N.O. (normally open)
relay #3 common
relay #3 N.C. (normally closed)
relay #4 N.O. (normally open)
relay #4 common
relay #4 N.C. (normally closed)
SETUP > ADVANCED OPTIONS > ALARMS.
Communications Setup
Wire Color
green
black
white
green
black
white
87. When an alarm is
Table 29 shows each Trouble
69