Self Test; Self Test After Connection To The Supply Voltage; Automatic Self Test; Manual Self Test - Bender ISOMETER isoPV1685RTU Manual

Function

3.4 Self test

3.4.1

Self test after connection to the supply voltage

Once connected to the supply voltage, all internal measurement functions, the compo-
nents of the process control such as data and parameter memory as well as the connections
to earth are checked. Once the self test is finished, after approx. 5 s the normal measure-
ment mode begins.
If a device error or a connection fault is detected, the corresponding alarm will be signalled
via the CAN and the RS-485 interface as well as via the alarm relay K3 (31-32-34). This relay
continuously operates in N/C operation, i.e. it de-energises even in case of a complete de-
vice failure. During this self test, when the device is being started, the alarm relays K1 and
K2 are not switched.
3.4.2

Automatic self test

All supply voltages are continuously monitored.
The following tests are continuously carried out in the background:
• Connection E-KE
• System polarity
• Temperature measurement
• Measuring voltage generator
3.4.3

Manual self test

The self test is started via the CAN or RS-485 interface by a Modbus or BMS master with the
test button or by any CAN bus device.
Only in the manual self test mode (via the CAN or RS-485 interface), the following tests can
be carried out:
• Internal Flash
• Internal RAM
• CPU register
• Watchdogs
• Oscillator
• Function of the Iso measurement technique
• Restart of the device including re-initialising and recalibration (only when the test is
requested via RS-485 interface)
3.4.3.1 Manual self test via the RS-485 interface
During the manual self test via the RS-485 interface, the alarm relays K1 (11-12-14) and K2
(21-22-24) are switched. K3 is only shortly switched after a device restart .
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