MDC-40x cable
| Communication protocol | Ethernet |
|---|---|
| Last spectrometer | Active |
| Voltage protection | Undervoltage and overvoltage (18V max for the MDC-400, 35V max for the MDC-401 and MDC-402) |
| Connector A | RJ-45 |
| Connector B | None (flying leads) |
| Connector C | Lemo FGT.1M.308.XLMT |
| Dust caps | Lemo BGF.1M.100.CAV or BGF.1M.100.XAV (note: this dust cap protects the connector on the cable) |
The MDC-400, MDC-401 and MDC-402 communication cables can be used to connect a spectrometer to both a computer and a power source. Note that the cables are equipped with an under- and overvoltage protection circuit. This circuit protects the hardware against voltages which are too high (up to 60V) and against reverse polarity issues. The difference between the cables is the maximum voltage which is allowed to pass through. The MDC-400 blocks input voltages over 18V, while the MDC-401 and MDC-402 allows voltages up to 35V to be used. If you use a cable with an input voltage over 18V, make sure the spectrometer was designed to handle this voltage. The MDC-402 is identical to the MDC-401 cable in functionality, but contains other electronic components.
The Lemo FGT.1M.308.XLMT connector requires special tools to (dis)assemble. Please contact Medusa if the cable needs servicing.
Variants
| MDC-400 | Blocks voltages over 18V. |
|---|---|
| MDC-401 | Blocks voltages over 35V. |
| MDC-402 | Blocks voltages over 35V. Identical to MDC-401, but contains other electronic components. |
| MDC-403 | No protection |
Connection scheme
The connection scheme for the MDC-40x cable is shown below. Note that for both connectors, not all pins are in use. The voltage protection circuit built into the cable prevents the power line from being inspected using a multimeter.
Pin numbering
| RJ-45 |
| Lemo FGT.1M.308.XLMT Note: Pin numbering as seen from the back side. |
Pin description (Lemo connector)
| # | Description | Wire color |
|---|---|---|
| 1 | Power | Red and blue |
| 2 | Debugging only | Brown / white |
| 3 | Debugging only | Blue / white |
| 4 | Tx+ | Orange / white |
| 5 | Tx- | Orange |
| 6 | Rx+ | Green / white |
| 7 | Rx- | Green |
| 8 | Ground | Black and brown |
Notes
The MDC-40x cable is a regular network cable, designed to work with routers. The cable can be used for direct connection to a computer as well, but in some cases (particularly computers with old network cards) a crossover adapter may be required.