Vaisala HydroMet Guide de l'utilisateur télécharger pdf (Page 145)

Chapter 5 ____________________________________________________________ Technical Data

VAISALA______________________________________________________________________ 143

Dual RS-485 Module DSI486,

Version A

Channel A is always used in the RS-485 mode. In 2-wire RS-485, both

transmitted and received data is sent via this channel. In 4-wire RS-485,

this channel can either transmit or receive depending on the

configuration. Jumper X4 defines the line terminating resistor for the

data channel A. Remove the jumper X4 if you do not need the

terminating resistor of the dual RS-485 module. Figure 65 on page 143

provides a schematic wiring diagram for dual RS-485.

1006-101

Figure 65 Dual RS-485 Module Wiring Diagram

Channel B can be used either in the RS-485 mode or in the RS-232

mode. In 2-wire RS-485, both transmitted and received data is sent via

this channel. In 4-wire RS-485, this channel can either transmit or

receive depending on the configuration.

Figure 65 on page 143 provides a schematic wiring diagram for the dual

RS-485 connection, the dual 2-wire connection utilizing both channels.

The correct jumper settings for the channel B are listed in Table 33 on

page 143. The jumpers are located on the module as illustrated in Figure

66 on page 144.

Table 33 Jumper Settings for Channel B in the RS-485 Mode

Jumper Connected

Pins

Function

X3 1-2 Sets the RS-485 mode active for the channel

3-4

X6 1-2

X5 1-2 The line terminating resistor is in use with RS-

485.

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Vaisala HydroMet Guide de l'utilisateur Page 145