PMX_MULTI
User’s Manual
41
Basic Functions | Protection Functions and Alarms
Overheat protection (OHP)
Overheat protection (OHP) is activated when the product’s internal temperature rises to an abnormal level.
• When the product is used in an environment that exceeds its operating ambient temperature range
(0 °C to +40 °C).
• When the product is used with its air inlet or outlet port blocked.
• When the fan motor has stopped.
If you do not fix the problem that caused the overheat protection to be activated, OHP will be activated
again even if you turn the POWER switch off and on.
Communication monitoring (WATCHDOG)
The watchdog function monitors the SCPI command communication status.
Communication is assumed to have stopped if there is no communication within the time period specified
by the communication monitoring timer setting (CF24).
The function operates regardless of whether the product is in remote or local (panel control) mode. If you
are not using remote control (commands), set communication monitoring off using a timer setting.
In the alarm state, turn off communication monitoring before clearing the alarm.
Alarm input (ALARM IN)
The output of all channels is turned off when the PMX receives an alarm signal (0.5 V or less, or shorted
with pin 13) through pin 12 of the J1 connector when an abnormal condition occurs.
To apply an alarm signal, short the contact switch for at least 0.5 s. If the time is too short, the alarm may
not be detected.
Even when the POWER switch is turned off and then turned back on, if an alarm signal is being received,
ALARM IN will be activated again.
Alarm indication when OHP is activated
SELECT
OUTPUT
CH1
SELECT
OUTPUT
CH2
OUTPUT
ALL
CV
V
s
OFF
CC
A
s
ON
PRL
SER
TRACKING 12
LOCK
REMOTE
L AN
L AN
DEL AY
DEL AY SET
SET OVP
࣭
OCP
PRESET A B C
ALARM
CV
V
s
OFF
CC
A
s
ON
PRL
SER
TRACKING 12
%
%
%
%
Alarm indication when WATCHDOG is activated
SELECT
OUTPUT
CH1
SELECT
OUTPUT
CH2
OUTPUT
ALL
CV
V
s
OFF
CC
A
s
ON
PRL
SER
TRACKING 12
LOCK
REMOTE
L AN
L AN
DEL AY
DEL AY SET
SET OVP
࣭
OCP
PRESET A B C
ALARM
CV
V
s
OFF
CC
A
s
ON
PRL
SER
TRACKING 12
%
%
%
%
Alarm indication when ALARM IN is activated
SELECT
OUTPUT
CH1
SELECT
OUTPUT
CH2
OUTPUT
ALL
CV
V
s
OFF
CC
A
s
ON
PRL
SER
TRACKING 12
LOCK
REMOTE
L AN
L AN
DEL AY
DEL AY SET
SET OVP
࣭
OCP
PRESET A B C
ALARM
CV
V
s
OFF
CC
A
s
ON
PRL
SER
TRACKING 12
%
%
%
%
