RS485 Interfaces Description

The T200 provides an RS485 compatible communications interface on J2 and J3 (9-Sub-D Male and Female (Connector and Socket) on the T200 side). The RS485 port provides one to many communications. Two Sub-D connectors are provided to allow convenient daisy-chain connection of the RS485 cabling from one T200 to the next.

Figure 3.52: T200 Multi-Axis RS485 System

DAISYCHAINED RS485 CABLE

3.18.2.1 Wiring an RS485 Connection

The connector pins on the Serial Port 9-way D-Type connectors on the front-panel of the drive are as

Pin Number Function

1 Reserved for future use

2 CAN-Low

Table 3.12:- T200's RS485 Pinout on J2 and J3 (Same Pinout on both Connectors)

3.18.2.2 RS485 Adaptor for Conversion of RS232 to RS485

Recommended RS485 communication from a PC to a group of T200's is achieved by using an RS232/RS485 converter.

The RS232 side of the converter is connected to the selected communications port of the PC. The RS485 side of the converter is connected to the drive via the RS485 port (J2) of the T200.

RS485 communication is achieved by interfacing a suitable RS232/RS485 adaptor between the PC and drive. See Section 7 for recommendations on installing an RS485 interface with the WinDrive user interface

Adaptor Requirements

The following adaptor and cable requirements should be met by any adaptor that is used with Moog's WinDrive user interface.

• Half Duplex Operation (Data Signals are both transmitted and received on two pairs wired in parallel (i.e. Tx/Rx (A)

= RS485+, and Tx/Rx (B) = RS485-).

• Method of Enabling of Transmitter of adaptor from the P.C. (e.g. use TxData line to enable adaptor transmission on the RS485 line).

• Tx+ and Tx- Pull up/down resistors, (values depend on Adaptor used.).

• Screened twisted pair (nominal impedance 120 Ω).

• Cable end termination with user supplied 120Ω resistors.

In Half Duplex operation, the RS485 side of the adaptor must be able to enable its transmitter when the adaptor is ready to transmit, and disable (i.e. tri-state) the transmitter when the adaptor is ready to receive. Some adaptors use the RTS line from a PC' communications port as an enable signal to the transmitter. Other adaptors will implement the enabling of the transmitter internally.

CAUTION:- The RS485 Cable shield MUST be connected to the metal body of the D-Type connector, in order to provide a good galvanic connection between the host computer and the T200 local signal ground. If this is not done then RS485 communications may be subject to spurious interruptions.

Example of PC Interface

If an external signal is required to enable the transmitter of the adaptor, the Transmit Data pin from the PC can be used as an enable pin. An adaptor can be wired to ensure that the transmitter is enabled when data is sent, thus actively driving Highs on the RS485+ line.

If the RTS line is used by the adaptor, the following adaptor can be placed between the PC Communications port, and the RS232/485 Converter. WinDrive uses only the Transmit Data, Receive Data, and Signal Ground Pins on the PC Communications port.

Figure 3.53:- Adaptor between PC and RS232/RS485 Adaptor

For details of wiring for a specific RS232/RS485 adaptor, consult the data-sheet for the particular device. The RS232/RS485 Adaptor recommended by MOOG for operation with WinDrive and the RMC/DMC and T200 is PSM-EG-RS232/RS485-P/2D, PN2761392 from Phoenix Contact.

PHOENIX RS232

PC COM PORT SIGNAL 9-PIN D COMBICON

1 SHLD NC NC

2 RXD 2 5

3 TXD-RTS 3 & 7 4 & 7

5 GND 5 8

PHOENIX RS485

T200 RS485 SIGNAL 9-PIN D COMBICON

4 RS485 + 3 6

5 RS485 - 8 8

6 GND 2 - 7 4

Table 3.13:- Wiring of PSM-EG-RS232/RS485-P/2D

For further information consult MOOG applications engineering.

3.18.2.3 RS485 Line Termination

RS485 lines must be terminated in 120Ohm resistance, at each end of the cable, between the positive and negative terminals (RS485+ and RS485-). Figure 3.54 below does not show a 120 Ω resistor at the adaptor end as this is presumed to be part of the adaptor circuitry.

4 5 RS485+

RS485-Connector J2

T200

26AWG (0.15mm²) Wiring RS485 Adaptor

Figure 3.54:- RS485 Wiring and Termination

3.18.2.4 RS485 Cable Maximum Length

The maximum combined length of all RS485 cabling is 1000m. Combined length is the sum of all cable segments, including the cable from the RS485 adaptor to the first T200, and between subsequent T200's and the next, and so on to the end of the cable.

3.18.2.5 RS485 Address Set-up via Axis-ID-HEX-Switches on T200 front Panel

A unique RS485 address must be assigned to each T200 in an RS485 network. The two Node ID switches are used to set this address. Note that a fine screwdriver should be used to set the HEX switches to the appropriate value. Node addresses start at 1, rather than 0. The node address 0 is reserved for broadcast messages via RS485.

Figure 3.55:- Axis ID HEX Switches Location

3.18.2.6 RS485 Set-up Parameters

The following port parameter settings are used to communicate with the T200 via the RS485

link:-§

9600 baud

§

8 data bits

§

1 stop bit

§

no parity bits

§

no hardware control/handshaking.

The T200 has two HEX (modulo-16) Switches that should be set to the axis identification number of the T200.

Modulo-16 means that the number range that can be selected is from 0 to 15.

Numbers in the range 10 to 15 are

represented by A to F. For example, to set the axis identification number to 29, the top switch should be set to 1 and the bottom switch to D,

29 = 16 by 1 plus 13 and

13 = D in the modulo 16 representation.

These switches are located on the front panel of the T200 and are accessible without opening the T200. The upper most of the two switches is the most significant.

MSB LSB

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