Omron E5ZD, Operation Manual

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6
•
You must allow at least 10 ms between the host computer receiving a response
and it sending the next command.
•
If the terminator switch is set incorrectly, current consumption may increase
and communications may not be possible. Turn ON the terminator switch only
for the terminator, and leave it OFF for all other Units.
•
The command which has the longest response time (from the time the com-
mand is received until the beginning of the response) is the WE command,
which transfers RAM data in blocks. For processing this command, it may take
up to 3.5 seconds for the set data to be transferred for Fuzzy-logic Controllers
and up to 2.3 seconds for other Controllers. It is therefore necessary, when
processing communications, to take into account that the response may be
delayed after the command has been transmitted. In addition, if the power is
cut before the transmission of the response has been completed, the contents
of the settings will not be saved.
•
When E5ZD Units are used simultaneously with differing numbers of control
points, or if an E5ZD is replaced by another Unit with a different number of con-
trol points, then be sure to take that into consideration when creating the pro-
gram at the host. There may be differences in the number of response data for
global read operations depending on the number of control points.
•
If you are using
°
F as the setting unit, there may be a setting error after the DIP
switch is changed from
°
C to
°
F. This is because the settings that were being
used for
°
C are not automatically converted when the unit is changed to
°
F, and
the
°
F temperature range may thus be exceeded. For example, suppose that
an initial value of 0 is set at the time of factory shipment. If the temperature
range is set as 32
°
F to 752
°
F for thermocouple K, then the initial value of 0 will
be outside of the range and a setting error will be generated. After changing
DIP switch settings, you should re-initialize E5ZD settings, clear setting errors
and make settings within the correct range, and write the values into nonvola-
tile memory using the WE command.
•
The inputs used to designate the current memory bank are level inputs and
must retain their status to maintain the same memory bank designation.
•
Do not leave unused inputs, including thermocouple and platinum resistance
inputs, unconnected. When not required, connect dummy inputs as follows:
thermocouple input, short circuit the positive and negative terminals; platinum
resistance input, connect from 100
Ω
to 177
Ω
between terminals A and B, and
short circuit between the B terminals. Leaving these terminals unconnected
will result in operating errors.
•
With platinum resistance input specifications, there is no insulation between
sensor input points.
•
There is no insulation between sensor inputs and CT inputs.
•
For E5ZD-8H
j
KJM-E sensor input, it is necessary to use a special terminal
block for thermocouple inputs. This special terminal block includes an element
which conducts cold junction compensation, and therefore a cold junction
compensation error will be generated if the special terminal blocks are not con-
nected both to the connector for points 0 to 3 and the connector for points 4 to
7. If an error is generated, the temperature cannot be controlled at any of the
points. Therefore it is necessary to connect two terminal blocks even if only
four points are to be used.
•
Turn on the power for the heater before activating the HB alarm. If the power for
the heater is turned on late, the HB alarm may be turned ON.
•
There may be a difference between the rated current for the heater and the
current that the heater is actually drawing. When making the setting for the
heater burnout detection level, therefore, use the command for measuring the
current while the heater is actually used, and then take that value as the basis
for making the setting.
Precautions
Section 1-4