MAx Wiring

The MAx module can be wired to MDT and SSI transducers. Each axis on the MAx also has a Fault input, Enable output, and a Control output. If the MA module has two axes, each axis' pinout is identical.

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. See Wiring Guidelines for general wiring information.

Wire clamp screws must be tightened to max 7 b-in (0.8Nm).

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 manufacturer's documentation.

Pin-Out

Pin #	MA1 Label	MA2 Label	Function
1	+Fault In	Flt In+	Fault Input
2	-Fault In	Flt In-	Fault Input
3	+Enable Out	En Out+	Enable Output
4	-Enable Out	En Out-	Enable Output
5	Control Out	Ctrl Out	Control Output
6	Common	Cmn	Common
7	+Int/Clock	Int/Clk+	MDT Interrogation or SSI Clock
8	-Int/Clock	Int/Clk-	MDT Interrogation or SSI Clock
9	Common	Cmn	Common
10	+Ret/Data	Ret/Dat+	MDT Return or SSI Data
11	-Ret/Data	Ret/Dat-	MDT Return or SSI Data
12	Case	Case	Connected to RMC Chassis

The commons are internally connected.

MDT Wiring (see below for SSI)

The MAx modules interface only to transducers with Differential Line Driver (RS422) signals. Single-ended (TTL) transducers are not supported due to low noise immunity. MDT transducers connect to the following MAx pins:

Pin	Function	Additional Possible Manufacturer Designation
Int/Clk +	MDT + Interrogation	Interrogate + Input
Int/Clk -	MDT - Interrogation	Interrogate - Input
Cmn	MDT Common
Ret/Dat +	MDT + Return	Pulse + Output
Ret/Dat -	MDT - Return	Pulse - Output
Case	RMC75 Chassis

Wiring instructions:

Connect the '+Int' and '-Int' between the transducer and the MA module for the interrogation signal.
Connect the '+Ret' and '-Ret' between the transducer and the MA module for the return signal.
Connect the transducer DC ground to Cmn. Each axis has two Cmn pins. Either of the 2 pins may be used. The Cmn must be connected to the transducer, or the signals will not be read correctly!
The transducer power supply is not provided by the RMC. The user must supply a power supply. The power supply common may be connected to the same common that is connected to the RMC75 CPU Cmn.

Diagram

SSI Wiring

SSI uses differential line driver (RS422) clock and data signals. Connect the transducer DC ground to SSI Cmn. SSI transducers connect to the following MAx pins:

Pin	Function
Int/Clk +	SSI + Clock
Int/Clk -	SSI - Clock
Cmn	Common
Ret/Dat +	SSI + Data
Ret/Dat -	SSI - Data
Case	RMC75 Chassis

Max Cable Length

SSI Clock Rate	Maximum Cable Length*
150 kHz	1360 ft (415 m)
250 kHz	770 ft (235 m)
375 kHz	475 ft (145 m)

* The cable lengths are approximate, and may be affected by the type of wire and transducer.

Wiring Instructions

Connect both the +Clock and -Clock between the MA module and transducer for the clock signal.
Connect both the +Data and -Data between the MA module and transducer for the data signal.
Connect the transducer DC ground to Cmn. Each axis has two Cmn pins. Either of the 2 pins may be used. The Cmn must be connected to the transducer, or the signals will not be read correctly!
The transducer power supply is not provided by the RMC. The user must supply a power supply. The power supply common may be connected to the same common that is connected to the RMC75 CPU Cmn.

Diagram

Fault Input Wiring

The Fault input is compatible with signal levels ranging from 12V to 24V. The Fault Input draws 2.7mA maximum and turns on at 6V. The Fault input turns on when a current flows. The polarity of the voltage is unimportant. See the Fault Input topic for more details.

Fault input wiring diagrams:

Generic:

From Open Collector Output:

Enable Output Wiring

The Enable output is a solid state relay (SSR). When it is off, it has high impedance, and when on it has low impedance (10 Ω maximum). Because the Enable output is isolated, the user must power it externally. The maximum current and voltage for the Enable output is 100 mA and 30 V.

The Enable output has a + and - connection. Both lines must be connected for the output to function. Because both sides of the output are provided, the switches may be independently connected in a high side or low side configuration (that is, with the load (input) on the source or sinking side of the output). See the wiring diagrams below.

See the Enable Output topic for more details on the Enable Output.

To TTL input (high = enable):

To active low Enable input:

Using Outputs with Inductive Loads

External fuses should be used to protect the SSRs if there is a possibility of over-current. When switching inductive loads, it is important to place a diode or tranzorb across the load to protect the switch when transitioning from an “ON” to an “OFF” state. Otherwise, the collapsing magnetic field can cause a reverse voltage spike in excess of the 30 V rating of the SSR.

Control Output Wiring

The valve or motor drive connects to the following MAx pins:

Pin	Function
Control Output	Control Output
Cmn	Control Output Common. Each axis has two Cmn pins. Either of the 2 pins may be used.

See the Control Output topic for more details on the Control Output.

Note:
The Control Output polarity can be set with the Invert Output Polarity parameter.