11 Technical Appendix
11.8.14 MRI - Standard Reference Input Signals
If an application requires to use external synchronization sources instead of radio/GNSS signals, an MRI card
enables the installed clock module to synchronize to 1PPS, 10 MHz, DCLS and AM time codes (IRIG B,
AFNOR, IEEE1344 or C37.118).
Each MRI card is dedicated to one clock module, if a redundant solution requires external synchronization
inputs for both clock modules, two MRI cards have to be installed. The MRI card is available with 4x BNC
connectors.
Reference Inputs:
Time Code unmodulated input
(DCLS)
BNC connector, isolated by opto-coupler
Insulation voltage:
3750 Vrms
Internal series resistor:
330 Ohm
Max. input current:
25 mA
Diode forward voltage:
1.0 V - 1.3 V
selectable Time Code Inputs, modulated / unmodulated (DCLS):
B122/123 / B002/003 / B126/127 / B006/007
IEEE1344 (modulated and DCLS)
AFNOR NFS 87-500 (modulated and DCLS)
Time Code modulated input
(AM),
BNC connector, isolated by transformer
Insulation voltage:
3000 V DC
Input impedance:
50 Ohm, 600 Ohm, 5 kOhm
Internally selectable by jumper
(default 600 Ohm)
Input signal:
600 mV to 8 V (Mark, peak-to-peak)
10 MHz input
, sine (1.5 V
pp
- 5 V
pp
)
or TTL, female BNC connector
PPS input
, TTL, pulse duration
≥
5
µ
s,
active high, female BNC connector
Figure right:
MRI - standard input signals
via BNC female connectors
IMS - LANTIME M4000
Date: 27th May 2021
87
