Meinberg IMS-GPS180 User manual

MANUAL
IMS-GPS180 Setup Guide
Hot-Plug Module
10th January 2018
Meinberg Radio Clocks GmbH & Co. KG

Table of Contents
1 Imprint 1
2 Safety Instructions for hot pluggable Modules 2
2.1 AdditionalSafetyHints ........................................... 3
2.2 SupplyVoltage ................................................ 3
2.3 Cabling..................................................... 4
3 Replacement or Installation of a Hot-pluggable IMS Module 5
4 GPS Clock 6
4.1 Configuration of IMS Modules via Web Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1.1 Clock ................................................. 8
4.2 Meinberg GPS Antenna/Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2.1 Introduction.............................................. 25
4.2.2 Mounting and Installation of the GPS Antenna . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.3 PoweringupaGNSSReceiver....................................... 27
Date: 10th January 2018 IMS-GPS180 Setup Guide

1 Imprint
1 Imprint
Meinberg Funkuhren GmbH & Co. KG
Lange Wand 9, 31812 Bad Pyrmont / Germany
Phone: + 49 (0) 52 81 / 93 09 - 0
Fax: + 49 (0) 52 81 / 93 09 - 30
Internet: http://www.meinberg.de
Mail: [email protected]
Date: 2017-05-31
IMS-GPS180 Setup Guide Date: 10th January 2018 1

2 Safety Instructions for hot pluggable Modules
Check before every maintenance work on the system:
•If a data backup is required?
•Is a backup required, verify the data recovery which is done by this backup.
•Make sure to avoid any static discharge while working - use a grounding cable and/or antistatic gloves
during installation and removal of hot pluggable components.
•If you are replacing a hot pluggable power supply, unplug the power cable prior to removing the module
from the case.
•Never open a power supply. In power supplies dangerous voltages can still remain even after disconnection
from the power supply. Always send power supplies back to the manufacturer for maintenance.
Exchange of hot-swap components
•Ensure that components which will be replaced during operation, always be treated with the utmost care.
Avoid contact with live components.
•Electrostatic discharge can damage electronic components. For this reason, ensure protection against
electrostatic discharges by wearing anti-static shoes while working with the system.
•Take care when removing and installing the hot-plug modules. Always work with the utmost caution.
Touch the modules only at the edges.
•Place the module out of the box or after removal from the system with the component side to the top on
a grounded and static-free surface.
•Storage of an IMS module must be done in a dry place.
•Installation or removal from hot-swap components only by authorized personnel!
2 Date: 10th January 2018 IMS-GPS180 Setup Guide

2 Safety Instructions for hot pluggable Modules
2.1 Additional Safety Hints
This manual contains important information for the installation and operation of this device as well as for your
safety. Make sure to read carefully before installing and commissioning the device.
Certain operating conditions may require the observance of additional safety regulations not covered by this
manual. Nonobservance of this manual will lead to a significant abatement of the security provided by this
device. Security of the facility where this product is integrated lies in the responsibility of the installer.
The device must be used only for purpose named in this manual, any other use especially opteration above the
limits specified in this document is considered as improper use.
Keep all documents provided with the device for later reference.
This manual is exclusively for qualified electricians or by a qualified electrician trained personnel who are
familiar with the applicable national standards and specifications, in particular for the construction of high
voltage devices.
2.2 Supply Voltage
WARNING!
This device is powered by a dangerous voltage. Nonobservance of the safety instructions of this manual may
lead to serious damage to persons and property and to danger to life! Installtion, commissioning, maintenance
and operation of this device are to be carried out by qualified personnel only.
The general safety instructions and standards ( e.g. IEC, DIN, VDE, EN ) for installation and work with
high voltage equipment as well as the respective national standards and laws must be observed.
NONOBSERVANCE MAY LEAD TO SERIOUS DAMAGE TO PERSONS AND PROPERTY AND TO DAN-
GER TO LIFE!
The device may not be opened. Repair services may only be carried out by the manufaturer.
Supply lines for this decice must be equipped via an appropriate switch that must be mounted close to the
device and must be marked as a mains switch for the device.
To ensure safe operation supply mains connected to this decice must be equipped with a fuse and a fault-
current circuit breaker according to the applicable national standards for safe operation.
The device must be connected to a protective earth with low grounding resistance according to the applicable
national rules.
IMS-GPS180 Setup Guide Date: 10th January 2018 3

2.3 Cabling
WARNING!
DANGER TO LIFE BY ELECTRICAL SHOCK! NO LIVE WORKING!
Wiring or any other work done the connectors particularly when connectors are opened may never be carried out
when the installation is energized. All connectors must be covered to prevent from accidental contact to life parts.
ALWAYS ENSURE A PROPER INSTALLATION!
4 Date: 10th January 2018 IMS-GPS180 Setup Guide

3 Replacement or Installation of a Hot-pluggable IMS Module
3 Replacement or Installation of a Hot-pluggable
IMS Module
Please use a Torx screwdriver (T8 x 60) for removal and installation.
1. Follow the safety instructions at the beginning
of this manual!
1. Remove the two marked Torx screws from the
module holder plate or the cover plate of
the empty slot.
2. (Only for an already built-in module)
Pull the module carefully out of the holding
rail. Note that the module is firmly anchored
in the connector block of the housing. You need
a certain amount of force to release the module
from this link. Once the connection to the
connector block of the system’s backplane is
loosened, the module can be easily pulled out.
3. When installing the new IMS module, please ensure that the board is correctly inserted into the
two guide rails of the system housing. Non-observance can cause damage to the module and the chassis.
Make sure that the module is securely locked into the connector block before you fasten the two screws.
4. Now you can put the installed module into operation.
Attachment points of an 1U IMS system
IMS-GPS180 Setup Guide Date: 10th January 2018 5

4 GPS Clock
Receiver: 12 channel GPS C/A-code receiver
Accuracy Depends on oscillator option:
of pulse outputs: < +-100 ns (TCXO, OCXO LQ)
< +-50 ns (OCXO-SQ, -MQ, -HQ, -DHQ)
Antenna Cable: shielded coax
Cable Length: max. 300 m to RG58,
max. 700 m to RG213
Antenna Connector: BNC female
Input GPS: Antenna circuit
1000 V DC insulated
Local Oscillator
to Converter Frequency: 10 MHz 1
First IF Frequency: 35.4 MHz 1
1) these frequencys are
transfered via the antenna cable.
Power Requirements: 15 V, 100 mA (via antenna cable)
Figure right: GPS Receiver and
GPS with XHE-SPI Connector (optional)
LED Indicators
Init: blue: while the receiver passes through
the initialization phase
green: the oscillator has warmed up
Nav.: green: positioning successfully
Ant: red: antenna faulty or not connected
yellow: the clock is synchronized by an external Signal - MRS mode (PPS, IRIG ...)
Fail: red: time has not synchronized
6 Date: 10th January 2018 IMS-GPS180 Setup Guide

4 GPS Clock
Pin Assignment of the DSUB9 Connectors (male):
Pin 2: RxD
Pin 3: TxD
Pin 5: GND
Pin Assignment of the optional XHE-SPI Connectors:
A1: PPS In
A2: PPS Out
Pin 1: SCL_Out (SPI Clock)
Pin 2: CS (Chip Select)
Pin 3: MOSI (Master Out, Slave In)
Pin 4: MISO (Master In, Slave Out)
Pin 5: GND
Attention: Use this plug only to connect a MEIN-
BERG IMS-XHERb Rubidium expansion chassis.
IMS-GPS180 Setup Guide Date: 10th January 2018 7

4.1 Configuration of IMS Modules via Web Interface
This chapter shows how to configure a IMS clock module, for example a GPS receiver.
4.1.1 Clock
On this page of the web interface, configurations can be made on the respective installed reference clocks or
the changeover card.
Depending on the design of the system, which means whether it is a single reference clock or a system with two
installed remote clocks and a changeover card, the web interface builds up accordingly. This also applies to the
type of reference clock and its options. In case of a redundant receiver configuration the common settings for
"IRIG In/Out", "Serial Ports", "Time Zone", "Enable Outputs", "Programmable Pulses" and "Synthesizers" appears
into the "Switch Card" menu.
Figure: Menu "Clock" in case of a single receiver
8 Date: 10th January 2018 IMS-GPS180 Setup Guide

4 GPS Clock
MRS Status
Here the states of the reference inputs are shown:
Priority: Arrangement of the time source according to your prioritization.
Source: Type of reference source.
Status: No Connection,
No signal →the reference source is not available.
Signal available →the reference source is available.
Is master →the reference source is used to synchronize the system.
Is locked →the system synchronizes itself to the reference source.
Is accurate →Basic accuracy of synchronization reached.
Offset: Time difference of the reference clock to the specified time source.
Statistics: Span →If the difference between the min / max value
of the time source is over a defined statistical
interval.
Step-Compensation →Displays a hard time jump of the reference source
(currently only available for PTP).
Auto-Bias →Time offset determined for the source versus an
offset-free time source.
IMS-GPS180 Setup Guide Date: 10th January 2018 9

MRS Settings
The MRS stands for a Multi Reference Source clock. This is a special functionality of a receiver that can in
addition to GNSS use also other input signals as a reference for synchronization.
MRS Source Priority
In the MRS Settings you can configure a priority list of input signals how the switching will follow in case that
a master reference becomes unavailable . The selection of signals in the list is automatically generated by the
LANTIME according to the hardware configuration. The priority list of input signals should be configured in a
descending order referring to the accuracy of signals.
Here is an example how to configure a priority list in a descending order:
1. Source: GNSS / GPS
2. PPS + String
3. PTP – IEEE1588
4. external NTP Server
10 Date: 10th January 2018 IMS-GPS180 Setup Guide

4 GPS Clock
IRSA - Intelligent Reference Selection Algorithm
IRSA stands for an Intelligent Reference Selection Algorithm. In case that a master signal fails the IRSA takes
care that the switching to the next reference signal in the priority list runs automatically and smoothly. The
IRSA also takes into account the highly stable holdover performance of the local oscillator. It ensures that
switching from the superior reference signal to the less accurate one is delayed as long as the highly stable
oscillator can provide better accuracy in holdover than the next available reference signal in the priority list.
To ensure that IRSA is working properly, follow these steps:
1. Configure a priority list of available reference signals in descending order from the superior to inferior
one in the MRS Settings menu (see chapter MRS Source Priority).
2. Activate IRSA in the IRSA menu. As per default the IRSA is deactivated.
3. Fill in the estimated precision values for the input reference signals in for this provided precision fields.
The precision value will determine the holdover time when switching to the next reference source if the current
master is not available.
Here are some estimated precision values which you can load as defaults:
- GPS / GNSS as the first priority has the highest estimated precision :100 ns
- ext. Osc. (e.g. Rubidium): 120 ns
- PTP IEEE 1588: 100 ns
- PPS plus string: 100 ns
- NTP: 100 us
IMS-GPS180 Setup Guide Date: 10th January 2018 11

MRS Features
Advanced Source Selection
A firmware V6.24 and the following versions support a mixed combination of reference signals for synchroniza-
tion. In the mixed mode you can select one source only for the ToD (Time of Day) synchronization and another
source for phase and frequency. The phase and frequency can be provided by a highly stable and accurate
source, for example an atomic clock, like Rubidum or Cesium.
The Time of Day (ToD) information represents a “wall clock time” – a specific time with hours, minutes, seconds
and the corresponding date. The ToD information cannot be delivered by an atomic clock alone. Therefore,
if you need the ToD in your system, you need to select one of the reference signal which includes the ToD
information, for example GPS, NTP, PTP, PPS plus string.
If you use the mixed mode the reference clock will be steered first by a reference signal which includes the ToD.
The oscillator will be roughly adjusted until it reaches the highest level of accuracy that can be achieved by
this reference. After that the reference clock switches automatically to a more accurate source, for example a
1PPS coming from an external atomic clock that provides highly stable phase or a 10MHz signal to provide a
stable frequency.
As per default both ToD and Phase are enabled for each available reference source. If you want to use
the mixed mode, then select the ToD for one reference signal and phase for another. The reference sources
you wish to use should be configured first in the Source Priority list. See MRS Settings →MRS Source Priority.
Here is one configuration example for Advanced Source Selection:
12 Date: 10th January 2018 IMS-GPS180 Setup Guide

4 GPS Clock
Extended Options
The Trusted Source (TRS) feature is a powerful tool to protect the GNSS1receiver from spoofing attacks. For
the moment, the Trusted Source feature is supported only in combination with a Meinberg GPS or GNSS
receiver and a Meinberg XHE external Rubidium holdover unit.
To activate this feature, select "Use Trusted Source" check box for the GPS reference signal. It means that
GPS reference will be checked for consistency by another reference source which is acknowledged as a Trusted
Source. In our case the trusted source is a Rubidium atomic clock. It is denoted as ext.Osc. (external oscillator)
in the table of Extended Options. Therefore select this check box "Is Trusted Source".
The external Rubidium acts as an external oscillator that is synchronized by the GPS or GNSS Master as
long as the master is available and its precision is better than the precision of the XHE. If the Master fails
or for some reason uses corrupted or manipulated data the TRS will detect this as an offset limit violation.
Consequently, the reference selection algorithm will discard the current master and the XHE Rubidium source
will become the new master for synchronization.
Both GNSS and Rubidium reference signals need to be configured first in the Source Priority list, GPS or
GNSS as "Source 1" and external Oscillator as "Source 2". All other positions should be left empty (see chapter
MRS Source Priority).
Second, the IRSA Reference algorithm should be activated with corresponding precisions (see chapter IRSA -
Intelligent Reference Selection Algorithm).
The precision for GPS or GNSS is at same time also the TRS limit, that the reference should comply with. If the
TRS limit is violated the reference selection algorithm discards the current master and switches automatically to
the Trusted Source - XHE Rubidium. For the GPS or GNSS precision value we take 250ns which is maximum
time deviation allowed for the receiver.
Finally, the GPS or GNSS source should have enabled "Time of Day Source" and "Phase Source", which
means that the receiver is a source for both Time of Day and Phase. At the XHE Rubidium only the Phase
Source should be enabled, since the atomic clock alone does not deliver the ToD information (see chapter MRS
Features).
1GPS / GNSS: The Trusted Source (TRS) feature will only work with GPS180 and GNS181 receivers.
IMS-GPS180 Setup Guide Date: 10th January 2018 13

IRIG Settings
Depending on the system configuration, the configuration of the incoming and / or outgoing time codes can
be configured in this menu. There are three common time codes:
IRIG B002+B122 - IRIG-B 100pps:
DC Level Shift (DCLS), No carrier(DCLS),
Time coding (HH,MM,SS,DDD)
Modulated, 1 kHz / 1 millisecond resolution,
Time coding (HH,MM,SS,DDD), Control Functions
B003+B123 as well as B002+B122, with second of day (0....86400)
AFNOR NF S87-500 AFNOR NFS 87-500 is a standardized French timecode
similar to the IRIG code, but with additional information
such as day, day of month and year.
IEEE1344 In addition to a two-digit year, the offset to the UTC time, the current
daylight saving time status and announcements from the start and the end
of the summer time, as well as information about an upcoming leap second
are transmitted.
Input Code:
Configuration of the incoming IRIG / AFNOR / IEEE 1344 time code (MRS systems only).
UTC Offset:
If the applied timecode is impinged with a constant time offset to UTC, this time offset must be configured here,
so that the clock can convert the received time to UTC.
Output code:
If the system has direct TC output options, you can set the parameters in this menu section.
Time Scale:
The output of the selected time code can be done with UTC or the local time. When "LOCAL TIME" is used, it
refers to the configuration of the menu point "Time zone".
14 Date: 10th January 2018 IMS-GPS180 Setup Guide

4 GPS Clock
Serial Interfaces
Depending on the number and version of the system, the parameters for the serial interfaces can be configured
in this menu.
Baudrate: The speed with which the serial telegram is to be transmitted:
300, 600, 1200, 2400, 4800, 9600, 19200
Framing: Structure of the telegram:
7E1, 7E2, 7N2, 7O1, 7O2, 8E1, 8E2, 8N1, 8N2, 8O1
String Type: Configuration of the time telegram to be sent.
Mode: You can configure an interval (per second, per minute, on request "?" Only)
for the outgoing time string. If the operating mode is set on "Request", a
connected client must send a "?" to receive the time telegram in response.
Features:
MRS PPS Plus String
If the system has the MRS "PPS plus string" option, the baudrate and framing for the incoming time string must
be configured via this submenu.
Meinberg Capture *only for specific units*
This option is for systems that have a cap input. The event is triggered by a negative edge.
Two operating modes are available for the output of the capture time stamps, "on request ? Only" and "au-
tomatically".
on request "?" only
The triggered events are stored in a buffer of the reference clock. As soon as a "?" is sent to the reference clock
via a serial connection, the stored events are transferred from the buffer.
automatically
In this mode, the capture events are output directly on the serial interface.
IMS-GPS180 Setup Guide Date: 10th January 2018 15

Time Zone
In this menu, you can configure the time zones (offsets) for the output signals (IRIG, serial interface, pro-
grammable pulses) of the reference clock.
The data of the time zone are used from the time zone table (see chapter ?? System →Display).
Enabling the Outputs
Optionally, the outputs of the reference clock can be set to always supply a signal when the device is switched
on, or only when the internal clock is running synchronously.
16 Date: 10th January 2018 IMS-GPS180 Setup Guide

4 GPS Clock
Programmable Pulses
If the system has programmable switching outputs, you can configure the parameters in this menu.
Mode: Output signal configuration.
Pulse length (ms): Pulse length configuration.
Cycle: For "Cycle Pulse" mode, an interval can be configured in hh: mm: ss.
Time: In the configured mode "Single Shot", the time for the pulse can be parameterized
in hh:mm:ss.
DCF Suspend
After (min): In the "DCF77 Marks" mode, you can configure a shutdown time for the output port,
so that in the case of an asynchrony of the reference clock, no DCF mark is available
at the output.
On / Off Time: For the "Timer" mode, it is possible to configure start and stop times in hh:mm:ss.
Signal: Configuration of the output signal active in high or low.
Disable output
in Holdover mode: If the reference clock is asynchronous, the output signal is immediately deactivated
when the checkbox is activated.
IMS-GPS180 Setup Guide Date: 10th January 2018 17