MDT Wiring

Note: When positive voltage is sent to an axis’s drive, the axis must extend. The extend direction is defined as the direction that causes the transducer to return increasing counts. The extend direction of a magnetostrictive transducer is away from the head.

Use shielded twisted pairs for all connections to inputs and outputs. Route the transducer wiring separate from other wiring. You must provide the power supplies needed by your transducers.

RMC Magnetostrictive Transducer Input

Six-Pin Plug-in Terminal Block

Pin	Function
1	MDT Axis + Interrogation
2	MDT Axis - Interrogation
3	MDT Axis Common
4	MDT Axis + Return
5	MDT Axis - Return
6	Case

Note: The following example schematics do not include transducer pin numbers, color codes, or power supply requirements, since these vary between different transducers. To determine your power supply needs and connector pin-outs or cable color codes, consult your transducer manufacturers’ documentation.

The RMC can interface to transducers with either single-ended (TTL) or Differential Line Driver (RS422) interrogation signals. When wiring RS422 signals, connect both the '+Int' and '-Int' between the transducer and the RMC for the interrogation signal, and the '+Ret' and '-Ret' between the transducer and the RMC for the return signal. Connect the transducer DC ground to MDT Cmn.

$image\t_r_422.gif$

For a single-ended transducer with positive interrogation, connect the transducer '- interrogation in' wire to the ’r;MDT Cmn’ pin and the transducer '+ interrogation in' wire to the '+ Int' pin. CONNECT NOTHING TO THE '-Int' PIN OF THE RMC. Connect the transducer return plus wire to the '+Ret’ pin on the RMC and the transducer return common wire to ’r;MDT Cmn’ on the RMC. CONNECT NOTHING TO THE '-Ret' PIN OF THE RMC.

$image\T_R_SPOS.gif$

Temposonics I transducer users:

For the negative interrogation version of this transducer, connect the transducer '+ interrogation in' wire to the ’r;MDT Cmn’ pin and the transducer '- interrogation in' wire to the '-Int' pin. CONNECT NOTHING TO THE '+Int' PIN OF THE RMC. Connect the transducer return plus wire to the '+Ret’ pin on the RMC and the transducer return common wire to ’r;MDT Cmn’ on the RMC. CONNECT NOTHING TO THE '-Ret' PIN OF THE RMC.

$image\T_R_SNEG.gif$

Some Temposonics I transducers from MTS have 200 Ohm termination resistors installed between their interrogation pins and common. If yours do not, it may be necessary to install them as close to the transducers as possible to reduce electrical noise in the system.

RMC Drive Outputs

Four-Pin Plug-in Terminal Block

Pin	Function
1	Axis 0 Drive
2	Drive Common
3	Axis 1 Drive
4	Case

When positive voltage is sent to an axis’s drive, the axis must extend. The extend direction is defined as the direction that causes the transducer to return increasing counts. The extend direction of a magnetostrictive transducer is away from the head.

CAUTION: If the outputs from the RMC are reversed, the axis will be uncontrollable when power is connected. Confirm that your wiring is correct!