AMETEK i Series - Manual (Page 248)

User Manual
234 i Series / iX Series
9.7.2 LNS Option
The Line Sync Option (LNS) allows the output of the i/iX AC Source to be synchronized to the
line input. This capability may be needed to support tests that require the use of additional
equipment. The
–LNS option needs to be ordered at the time of purchase and cannot be
installed in the field.
The LNS Option – if installed – can be turned on from the front panel as follows:
Select the PROGRAM 2 screen and move the cursor to the CLK MODE field. The default value
for the field is INT for internal clock mode. Use the knob to select the SYNC mode in order to
enable the LNS. If the LNS is not installed a “LINE SYNC ERROR” will appear after a short
period in the top left of the screen. This means the LNS option is either not present or not
receiving a phase input signal from the line.
To turn the sync mode back off, set the CLK MODE field back to INT.
Over the bus, the LNS is enabled or disabled as follows:
FREQ:MODE SENS /* Enables LNS */
FREQ:MODE FIX /* Disables LNS */
If the LNS is not installed and the FREQ:MODE SENS command is issued, an error message is
generated. If done as part of a test program, an error check should be done after a 800 msec
delay to allow the i/iX to sense the presence of a sync signal coming from the LNS board. If no
error occurs, the LNS is active. If an error occurs, the LNS may not be available or not
functioning and the mode has reverted back to internal.
The LNS option is designed to keep the iX output frequency locked to the line frequency. There
is a finite phase offset however, between the iX source output and the line input to the iX power
source. This phase offset will vary somewhat with the input line voltage. If it is desired to have
the iX output in-phase with the line input it will be necessary to monitor the iX output voltage as
well as the line input to the iX source using a two channel oscilloscope to compare the zero-
crossings of the voltage waveforms. An isolation amplifier must be used when connecting the
input line to the o‟scope input. To program an offset angle on the iX source, go to PROGRAM 2
screen and select PHASE. Typically 25-30 of phase angle will put the line input and the source
output in-phase, but the exact angle to program can only be determined by monitoring the iX
source output and the line input voltage and comparing the waveforms.
9.7.3 XLS Option
The External Line Sync option (-XLS) is housed in a small metal enclosure that interfaces to the
power source using a system interface cable. This module has a pass-through connector for the
system interface so this interface remains available for other purposes.
The external line sync module provides two input voltage ranges, a low range from 80 V to 250 V
RMS and a high range from 250 V to 500 V RMS. The AC line voltage can be connected using
standard sheathed banana jacks or a screw terminal strip. The -XLS option provides full safety
isolation from input to interface connector. The AC line to synchronize the source output to can
be the same as the one feeding the source itself, or a different one altogether for greater
flexibility.