Siemens Milltronics BW500, Operating Instructions Manual

Page: 128 / 220

Communications
11.2 Connections
BW500 and BW500/L
126
Operating Instructions, 12/2016, A5E33482052-AD
11.2 Connections
WARNING
When a SmartLinx card is installed and P799 = 1, the parameters that the SmartLinx card
is writing to the BW500 and BW500/L will be continuously updated. Therefore, if you
connect a SmartLinx card to the BW500, set P799 = 1 and not write anything to the
SmartLinx card, your setpoints will be 0.
There are three serial communication ports on the BW500 and BW500/L:
Port Description
1 RS-232, Terminals 31 to 34
2 RS-485, terminals 35 to 40
3 RS-232, RJ-11 modular telephone jack
Refer to the Installation (Page 21) for wiring diagrams specific to each port.
11.2.1 Wiring Guidelines
Improper wiring and choice of cables are the most common sources of communication
problems. Listed below are some suggested guidelines:
• 15 meters (50 feet) for RS -232
• 1200 meters (4000 feet) for RS -485
• Ensure that communication cable is run separately from power and control cables (i.e. do not
tie wrap your RS-232 cable to the power cable or have them in the same conduit).
• cable is shielded and connected to ground at one end only
• 24 AWG (minimum)
• follow proper grounding guidelines for all devices on the bus
• use good quality communication gr ade (shielded twisted pairs) cable that is recommended for
RS-232.