HONEYWELL 05704-A-0121 ISS.03 QUAD RELAY INTERFACE CARD - 5704 Instructions

The RS232 Interface Module has transmit and receive data lines and two handshaking lines. The interface conforms to the RS232 standard giving ±12V output drive. Depending upon the type of installation, operation is possible over distances up to 15m (49ft). To protect the host computer against damage due to earth loops, the interface signals are isolated from the System 57 power supply 0V and Ground. The terminal connections are designated as follows: RXD Receive Data input to RTU. TXD Transmit Data output from RTU. DSR Data Set Ready input to RTU. DTR Data Terminal Ready output from RTU. SGND Isolated Signal Ground.

There are two versions of the Engineering Card. The MODBUS Interface Kit can only be fitted to the Mk 2 Engineering Card. With the Engineering Card removed from the rack, the type of Engineering Card can be visually identified as follows: a. Mk I hardware by the presence of only one 28 pin DIL IC socket on the card pcb. b. Mark II hardware by the presence of two 28 pin DIL IC sockets and a rectangular cutout near the centre of the card pcb. (See Figure 7). A summary of the MODBUS Interface installation procedure is shown below: a. Unpack and check the contents of the kit. b. Remove the Engineering Card from the rack. c. Install the Software Expansion EPROM Integrated Circuit. d. Install the RAM Expansion Integrated Circuit. e. Install the MODBUS Interface Module. f. Wire the DC Input Card terminal blocks to the host computer. g. Configure and Commission After installation is complete perform the commissioning procedures outlined in Section 5. The following sections provide a detailed explanation of the installation operations.

On receipt carefully unpack the equipment observing any instructions printed on or contained in the packaging. Check the contents for transit damage and ensure that the following items are present:

For the MODBUS Interface Module Kit: RS485/422: a. MODBUS Interface Module RS485/422 (05701-A-0282). b. Engineering Card Expansion Option EPROM integrated circuit (05701-A-0385). c. RAM expansion integrated circuit type HN6264ALP. d. User Manual (05701-A-5006). For the MODBUS Interface Module Kit RS232: a. MODBUS Interface Module RS232 (05701-A-0287). b. Engineering Card Expansion Option EPROM integrated circuit (05701-A-0385). c. RAM expansion integrated circuit type HN6264ALP. d. User Manual (05701-A-5006). 3.3 INSTALLING THE MODBUS INTERFACE KIT Except for Step (6) which applies to the RS485/422 Module only, the following installation procedure applies to both versions of the MODBUS Interface Kit: (1) Isolate the SYSTEM 57 Rack from all power sources. (2) Unscrew the two front panel screws that retain the Engineering Card and using the extraction tool supplied with the system pull the Engineering Card from the rack.

(3) Insert the Software Upgrade EPROM integrated circuit (05701-A0385) into the socket IC2 on the Engineering Card, ensuring that pin 1 of the IC is aligned correctly with pin 1 of the socket and that all pins are properly inserted into the socket. Note: If an IC is already fitted to socket IC2, this should be removed and discarded.

(4) Insert the RAM expansion integrated circuit (HN6264ALP) into the socket IC12 on the Engineering Card, ensuring that pin 1 of the IC is aligned correctly with pin 1 of the socket and that all pins are properly inserted into the socket. (5) Using small pliers or an electrical screwdriver gently remove the Engineering Card shorting link LK1 and replace to short pins 1 and 2. See Figure 7. (6) This step applies to the RS485/422 module only. For correct operation, especially at high baud rates, RS485 and RS422 highways should be resistively terminated. In RS422 host systems, a terminator resistance is only required at the receiver device located in the host and at the receiver device located in the System 57 node at the far end of the cable. In RS485 host systems, a terminator resistance is required at the transceiver device located in the host and at the transceiver device located in the System 57 node at the far end of the cable. For dual highway RS485 systems, both highways should be terminated as described above. By default the RS485/422 module transceivers are unterminated. If a resistive termination is required, use small pliers or an electrical screwdriver to gently remove the shorting links, LK2 (Channel 1) or LK1 (Channel 2), on the RS485/422 Module from pins 1 and 2 and replace to short pins 2 and 3. (See Figure 1 and Section 3.4.3). (7) Insert the MODBUS Interface Module into the socket headers J1 and J2 on the Engineering Card, ensuring that pin 1 of the module pin headers is correctly aligned with pin 1 of the Engineering Card socket headers. (8) Re-insert the Engineering Card into the rack, tighten the two front panel screws and go to the Section 3.4.