Emerson Rosemount Oxymitter 4000 Reference Manual page 60

Rosemount Oxymitter 4000
60
CAUTION
The HART option is not protected by energy limiting barriers. It must not be interfaced
from within the hazardous area. The 4-20 mA cables should be routed and the
connections made outside the hazardous area. Note that this is the case even when
using the intrinsically safe version of the handheld communicator.
Logic I/O
This two-terminal logic contact can be configured either as a solid-state relay-activated
alarm or as a bi-directional calibration handshake signal to an IMPS 4000 or SPS 4001B.
The configuration of this signal depends on the setting of the LOGIC I/O PIN MODE via
HART/AMS or LOI. The ten different modes available are explained in Table 3-1.
Alarm
When configured as an alarm, this signal alerts you to an out-of-spec condition. The
output is +5 Vdc in series with a 340 ohm resistor.
For optimum performance, Emerson recommends
connecting the output to a Potter & Brumfield 3.2 mA DC relay (P/N R10S-E1Y1-J1.0K).
Of the ten modes in Table 3-1, modes 0 through 7 are the alarm modes. The factory
default is mode 5 for Hazardous Area Oxymitter 4000 units without an IMPS 4000 or SPS
4001B. In this mode, the output will signal when a unit alarm or a CALIBRATION
RECOMMENDED indication occurs.
Calibration Handshake Signal
If using an optional IMPS 4000 or SPS 4001B, the logic I/O must be configured for
calibration handshaking. Of the ten modes in Table 3-1 only modes 8 and 9 are
configured for calibration handshaking. For a Hazardous Area Oxymitter 4000 with an
IMPS 4000 or an SPS 4001B, the factory sets the default to mode 8. In this mode, the
logic I/O will be used to communicate between the Hazardous Area Oxymitter 4000 and
the sequencer.
Configuration with Membrane Keypad
July 2018