Siemens TC12 Installation, Commissioning And Maintenance Handbook page 156

MONITOR MODE monitors i.e. receives both control and reply messages from the
line picking out the particular parts/messages associated with the selected/OTU
under test. Whilst continuing to allow free communications between Instation and
Outstations.
INSTATION MODE Simulates the Instation. In this mode the ITS isolates the line
(if connected at Instation) or the OTU (if connected at the OTU) from the Instation
and simulates the action of the Instation transmitting control data and receiving
reply data.
OUTSTATION MODE Simulates an Outstation. In this mode the ITS isolates the
line (if connected at Instation) or the OTU (if connected at the OTU) from the
Instation and simulates the action of the an Outstation transmitting reply data and
receiving control data.
4.4.2.2.2 OTU Info
On this screen all data pertaining to OTUs is entered i.e. Address/number of OTU
selected/under test, line identifier string, OTU identifier string, number of OTUs on
line and number of control and reply bytes for each OTU.
4.4.2.2.3 Transmission System
On this screen all data pertaining to transmission can be entered, plus a few
miscellaneous items, i.e. 2 or 4 wire, baud rate, full or half duplex, which signal
control/reply is to be measured for line level, where is ITS being used at Instation
or at Outstation, and delay before transmit (normally 0 i.e. transmit at exact
calculated time).
4.4.2.2.4 Data Entry/Testing
Once this screen has been entered testing is initiated. On this screen the state of
each bit of control and reply data for the selected OTU is displayed for 3 control
bytes and 14 reply bytes. When in Instation mode the control data can be
changed, (using cursor keys to select the bit and space bar to toggle its state).
When in Outstation mode the reply data can be changed, (using cursor keys to
select the bit and space bar to toggle its state). When in Monitor mode no data can
be changed the screen simply displays received data. The screen also indicates
the status of CRCs received and to be transmitted, whether transmissions are
occurring i.e. TX, whether carrier is being detected when receiving i.e. CD, what
mode the ITS is in, what transmit mode is active i.e. transmit on tick or when
prompted and if errors are being detected in received data i.e. Rx errors.
There are also a number of special/quick keys that are effective when in this
screen, to perform special actions.
USE F1 TO GET UP-TO-DATE HELP INFORMATION ON ALL SCREEN AND
KEY FUNCTIONS.
666/HE/43100/000
TC12 Installation, Commissioning & Maintenance Handbook
Page 146 Issue 10