Appendix A: Alarm And Timer Functions - Extech Instruments 48VTR User Manual

Appendix A: Alarm and Timer Functions

To select an Alarm function, use the 3
'11' are described below. To set an alarm setpoint use 'A1SP' in the 1
value for an Event or Soak timer, use the 'time' parameter in the 1
'00' Deviation High Alarm
The Alarm setpoint equals the Setpoint (SV) plus the 'A1SP' setting. For example, if SV = 400
and A1SP = +10 then the Alarm relay will trip when the temperature rises above 410
10 = 410).
'01' Deviation Low Alarm
The Alarm setpoint equals the Setpoint (SV) plus the 'A1SP' setting. For example, if SV = 400
and A1SP = -10 then the Alarm relay will trip when the temperature falls below 390
10 = 390).
'02' Process High Alarm
Relay trips when the process (PV) exceeds the 'A1SP' value.
'03' Process Low Alarm
Relay trips when the process (PV) falls below the 'A1SP' value.
'04' Deviation High Alarm with Standby Sequence
Same as the Deviation High Alarm but no relay action takes place until the PV reaches the SV
for a second time. Also known as 'Startup Inhibit' this selection is useful for avoiding alarm
trips during startup.
'05' Deviation Low Alarm with Standby Sequence
Same as the Deviation Low Alarm but no relay action takes place until the PV reaches the SV
for a second time. Also known as 'Startup Inhibit', this selection is useful for avoiding alarm
trips during startup.
'06' Process High Alarm with Standby Sequence
Same as the Process High Alarm but no relay action takes place until the PV reaches the SV
for a second time. Also known as 'Startup Inhibit', this selection is useful for avoiding alarm
trips during startup.
'07' Process Low Alarm with Standby Sequence
Same as the Process Low Alarm but no relay action takes place until the PV reaches the SV
for a second time. Also known as 'Startup Inhibit', this selection is useful for avoiding alarm
trips during startup.
'08' EVENT ON-Timer
Upon power-up the alarm is de-energized. When the PV = SV the timer starts but the alarm
relay remains de-energized. When the timer counts down to zero, the relay energizes. Set
the timer using the 'time' parameter in the 1
rd
Menu parameter 'A1Fu'. The available settings '00' to
st Menu Level. See Table below.
21
st Menu. To set a time
st
Menu.
48VTR User Manual v6.0 10/1/20
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o (400 –