JB2
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: +81(6)6659-8201 Fax: +81(6)6659-8510 E-mail: [email protected]
EM-2642 Rev.3 P. 5 / 5
■
DIFFERENCES BETWEEN JB AND JB2/A
Means to back up the output value is different.
JB: STATIC RAM (A large capacitance capacitor holds the value until the capacitor is discharged)
JB2/A: E
2
PROM (Output value is stored at E
2
PROM and held until the next rewrite)
JB: When power recovers during MAN control mode, the output value is different depending on the power fail period.
JB2/A: The output value at power recovery is selectable with ITEM 31. Refer to the following table.
OUTPUT VALUE AT POWER RECOVERY DURING “MAN” CONTROL MODE
JB
Output value at the moment of power failure
(recovery within the memory time)
Fixed value (recovery after the memory time)
JB2/A
ITEM 31 : 0
ITEM 31 : 1
■
COMPATIBILITY BETWEEN JB2 AND JB2/A
For JB2/A, the operation at power recovery is selectable (ITEM 30, 31).
When JB2 (without “/A”) is replaced with JB2/A compatibly, set JB2/A according to the ITEM 21 value of JB2 as following.
• When JB2 is set ITEM 21 as 1 (DIRECT) or as 2 (TRACE BACK)
Set JB2/A ITEM 30 as -25% and ITEM 31 as 0 (HOLD VALUE)
• When JB2 is set ITEM 21 as 3 (FIXED VALUE)
Set JB2/A ITEM 30 as -25%, and ITEM 31 as 1 (FIXED VALUE)
CHECKING
1) Terminal wiring: Check that all cables are correctly con-
nected according to the connection diagram.
2) Power input voltage: Check voltage across the terminal
7 – 14 with a multimeter.
3) Input: Check that the input signal is within 0 – 100% of
the full-scale.
4) Output: Check current across the terminal 2 (+) – 11 (–)
for MV output, 1 (+) – 10 (–) for the re-transmitted out-
put.
ADJUSTMENT PROCEDURE
This unit is calibrated at the factory to meet the ordered
specifications, therefore you usually do not need any cali-
bration.
For matching the signal to a receiving instrument or in case
of regular calibration, adjust the output as explained in the
following.
■
HOW TO CALIBRATE THE OUTPUT SIGNAL
Use a signal source and measuring instruments of sufficient
accuracy level. Turn the power supply on and warm up for
more than 10 minutes.
1) ZERO: Apply 0% CAS input and adjust the re-transmit-
ted output to 0%.
2) SPAN: Apply 100% CAS input and adjust the re-trans-
mitted output to 100%.
3) Check ZERO adjustment again with 0% CAS input.
4) When ZERO value is changed, repeat the above proce-
dure 1) – 3).
The MAN/CAS transition response time, UP/DOWN re-
sponse time (ramp rate), retroactive time period, CAS in-
put High/Low alarm setpoints are programmable using the
PU-2x Programming Unit. Refer to “FRONT VIEW & PRO-
GRAMMING.”
LIGHTNING SURGE PROTECTION
M-System offers a series of lightning surge protector for
protection against induced lightning surges. Please contact
M-System to choose appropriate models.
