Flowserve MX FOUNDATION Fieldbus Field Unit - Manual (Page 22)

MX/QX FOUNdaTION Fieldbus Field Unit FCd LMENIM2330-01 – 08/11
22
The maximum length of the fieldbus cable is determined by the following:
• Communication rate
• Cable type
• Wire size
• Bus power option
• Intrinsic safety option
The maximum number of devices on the MX/QX FF fieldbus segment is based on the following:
• The communication rates of the devices
• The maximum number of addresses on a segment.
• The available power
Table 2.5 – Recommended Maximum Spur Length, m (ft)
Spur Length m (ft)
Total Devices per
Network
1 Device
per Spur
2 Devices
per Spur
3 Devices
per Spur
4 Devices
per Spur
25-32 1 (3) 1 (3) 1 (3) 1 (3)
19-24 30 (98) 1 (3) 1 (3) 1 (3)
15-18 60 (197) 30 (98) 1 (3) 1 (3)
13-14 90 (295) 60 (197) 30 (98) 1 (3)
1-12 120 (394) 90 (295) 60 (197) 30 (98)
For further details on maximum cable length and number of devices, see the fieldbus references
listed in Section 2.6.2.2.
2.6.2.4 Network Cable Connection to the Host System (DCS)
For instructions on connecting to the DCS, see the applicable DCS instruction manual. There are
several possible topologies for the network as detailed in FOUNDATION Fieldbus Application Guide
AG-140, 31.25 kbits/s, Wiring and Installation.
2.6.3 MX/QX FF Device Installation
The MX/QX FF board is located in the electrical housing. The board has four standoffs and mounts on
top of the main processor board. If the I/O board option is present, the I/O board will be on top of the
MX/QX FF board. For installation instructions, refer to the MX Maintenance and Spare Parts Manual,
LMENIM2314 or the QX Maintenance and Spare Parts Manual LMENIM3314.
2.6.4 MX/QX FF Device Setup
The MX/QX FF option enables the actuator to be controlled by a Foundation fieldbus communications
signal. If the option has been purchased, it is automatically enabled.
NOTE: If the FF option has not been purchased, the screens for changing FF will not be available. To
add the FF option, please consult Limitorque service at (434) 528-4400.
Figure 2.16 illustrates the setup sequence. For proper operation either Position Mode or Open/Close
Mode must be selected.