Bender ISOMETER isoCHA425 Manual page 11

Function
3.2.10 Password protection (on, OFF)
If password protection has been activated (on), settings can only be made subject to the
correct password being entered (0...999).
3.2.11 Factory settings FAC
Activating the factory setting will reset all modified settings, with the exception of the in-
terface parameters, to the default upon delivery.
3.2.12 External, combined test or reset button T/R
Reset = Press the external button < 1.5 s
Reset followed by a test = Press the external button > 1.5 s
Stop measuring function = Press and hold the external button
The stop function can also be triggered via an interface command and in this case it can
only be reset via the interface.
Only one ISOMETER® may be controlled via an external test/reset button. A galvanic
parallel connection of several test or reset inputs for testing multiple insulation monito-
ring devices is not allowed.
3.2.13 Fault memory
The fault memory can be activated or deactivated with the parameter "M" in the "out"
menu. When the fault memory is activated, all pending alarm messages of the LEDs and
relays remain available until they are deleted by using the reset button (internal/external)
or the supply voltage U is turned off.
s
3.2.14 History memory HiS
When the first error occurs after clearing the history memory, all measured values (that
are ticked in the table on page 18) are saved in the history memory. This data can be read
out using the "HiS" menu item. In order to be able to record a new data record, the history
memory must first be cleared via the menu using "Clr".
11
Function
3.2.15 Interface/protocols
The ISOMETER® uses the serial hardware interface RS-485 with the following protocols:
• BMS
The BMS protocol is an essential component of the Bender measuring device inter-
face (BMS bus protocol). Data transmission takes place with ASCII characters.
• Modbus RTU
Modbus RTU is an application layer messaging protocol and it provides Master/Slave
communication between devices that are connected altogether via bus systems and
networks. Modbus RTU messages have a 16-bit CRC (Cyclic Redundant Checksum),
which guarantees reliability.
• IsoData
The ISOMETER® continuously sends an ASCII data string with a cycle of approxima-
tely 1 second. Communication with the ISOMETER® within this mode is not possible
and no additional transmitter may be connected to the RS-485 bus cable. The ASCII
data string for the ISOMETER® is described on
The parameter address, baud rate and parity for the interface protocols are configured in
the "out" menu.
With "Adr = 0", the menu entries baud rate and parity are not shown in the
menu and the IsoData protocol is activated.
With a valid bus address (i.e. not equal to 0), the menu item "baud rate" is
displayed in the menu. The parameter value "---" for the baud rate indica-
tes the activated BMS protocol. In this case, the baud rate for the BMS pro-
tocol is set to 9,600 baud. If the baud rate is set unequal to "---", the
Modbus protocol with configurable baud rate is activated.
The IsoData protocol can be cancelled by sending the command „Adr3"
during a non-transmission period of isoCHA425.
page 27.
isoCHA425_D00352_01_M_XXEN/10.2019