Yokogawa EJA115 - Manual (Page 22)

IM 01C22T02-01E 4-4
4. GETTING STARTED
4.6 Continuous Record of Values
If the host has a function of continuously records the
indications, use this function to list the indications
(values). Depending on the host being used, it may be
necessary to set the schedule of Publish (the function
that transmits the indication on a periodic basis).
4.7 Generation of Alarm
If the host is allowed to receive alarms, generation of
an alarm can be attempted from EJA. In this case, set
the reception of alarms on the host side. The example
using EJA differential pressure transmitter is shown
below. EJA’s VCR-7 is factory-set for this purpose.
For practical purposes, all alarms are placed in a
disabled status; for this reason, it is recommended that
you first use one of these alarms on a trial basis. Set
the value of link object-3 (index 30002) as “0, 299, 0,
6, 0”. Refer to section 5.6.1 Link Object for details.
Since the L0_PRI parameter (index 4029) of the AI1
block is set to “0”, try setting this value to “3”. Select
the Write function from the host in operation, specify
an index or variable name, and write “3” to it.
The L0_LIM parameter (index 4030) of the AI1 block
determines the limit at which the lower bound alarm
for the process value is given. In usual cases, a very
small value is set to this limit. Set 10 (meaning 10 kPa)
to the limit. Since the differential pressure is almost 0,
a lower bound alarm is raised. Check that the alarm
can be received at the host. When the alarm is con-
firmed, transmission of the alarm is suspended.
The above-mentioned items are a description of the
simple procedure to be carried out until EJA is con-
nected to Fieldbus. In order to take full advantage of
the performance and functionality of the device, it is
recommended that it be read together with Chapter 5,
which describes how to use the EJA.