266CRH / 266CRT, 266CSH / 266CST MULTIVARIABLE PRESSURE TRANSMITTER  |  OI/266CXX/MODBUS-EN REV. A  45 
 
 
 
 
Activation of the operating menu 
To access the operating menu, it must first be activated. 
 
Standard LCD indicator (option L1) 
For devices with standard LCD indicator, unscrew the housing 
cover with sight glass to obtain access to the display. When used 
in hazardous areas, always comply with the relevant directives 
before the housing is opened. 
Activate the   operating button to call up the configuration 
level. Activate the   operating button to call up the information 
level. 
 
LCD indicator with TTG technology (option L5) 
For devices with LCD indicators with TTG technology, activation 
can occur without opening the housing cover of the transmitter. 
The capacitive pickups that a person is taping with their finger 
on the glass over the appropriate operating button and triggers 
the appropriate command. 
When the transmitter is switched on, the operating interface 
automatically calibrates its sensitivity. Consequently to ensure 
trouble-free function of the operating interface with TTG 
function, the housing cover must be correctly screwed down 
when switching on the device. 
If in the meantime the housing cover has been removed, to gain 
access to the electronics module, we recommend that you 
switch the energy supply off and then on again, as soon as the 
housing cover with the sight glass has been correctly screwed 
down. 
 
Activation of the operating menu is executed as described: 
1.  Press the upper, middle operating button   and hold it 
until two symbols appear in the lower left and right in the 
display. 
2.  Within 1 second activate the operating button   below 
the right symbol to call up the configuration level, or left 
activate the operating button   to call up the 
information level. 
 
Notice 
If the contrast is out of adjustment to the extent that the display 
can no longer be read, the factory settings can be restored by 
simultaneous activation of the operating buttons   and  . 
 
 
 
 
 
 
Switching to the information level 
(operator menu) 
On the information level, the operator menu can be used to 
display diagnostic information and choose which operator 
pages to display. 
 
Process dis