Ametek JOFRA ASC301 User manual

Remote Manual
Advanced Signal Calibrators
JOFRA ASC301 & ASC321

1
Remote Operation
The calibrator can be remotely controlled using a PC terminal, or by a
computer program running the calibrator in an automated system. It uses an
RS232 serial port connection for remote operation. With this connection the
user can write programs on the PC, with Windows languages like Visual
Basic to operate the calibrator, or use a Windows terminal, such as Hyper
Terminal, to enter single commands. Typical RS232 remote configurations
are shown in Figure 1.
Figure 1. Calibrator-to-Computer Connection
1. Setting up the RS232 Port for Remote Control
Note: The RS232 connection cable should not exceed 15m unless the load
capacitance measured at connection points is less than 2500pF.
Serial parameter values:
9600 baud
8 data bits
1 stop bit
no parity
Xon/Xoff
EOL (End of Line) character or CR (Carriage Return) or both
To set up remote operation of the calibrator on the Windows Hyper Terminal,
connected to a COM port on the PC as in Figure 1, use the following
procedure:
1. Start Hyper Terminal (located in Accessories/Communications of the
Windows Start menu)
2. Select New Connection.
Optional RS-232 or USB Cable
(See section 7.4)
COM PORT USB PORT
OR
F1 F2 F3
CE
1
ENTER
HOME
23
456
789
-0.

2
3. For Name enter ASC301. Select the serial port that the unit is connected
to.
4. Enter the above information for port settings.
5. Select ASCII setup from File/Properties/Settings and mark these
choices:
Echo typed characters locally
Wrap lines that exceed terminal width
6. Select Ok
7. To see if the port works enter *IDN?. This command will return
information on the unit.
2. Changing Between Remote and Local Operation
There are three modes of operation of the calibrator, Local, Remote, and
Remote with Lockout. Local mode is the default mode. Commands may be
entered using the keypad on the unit or using a computer. In Remote mode
the keypad is disabled, and commands may only be entered using a
computer, but choosing [GO TO LOCAL] from the menu on the calibrator
display will restore keypad operation. In Remote with Lockout, the keypad
can not be used at all. To switch modes proceed as follows:
1. To enable Remote mode, type in the serial command REMOTE at the
computer terminal.
2. To enable Remote with Lockout, type in REMOTE and LOCKOUT in either
order.
3. To switch back to local operation enter LOCAL at the terminal. This
command also turns off LOCKOUT if it was on. For more information on
commands refer to the Remote Commands section.
3. Using Commands
3.1 Command types
Refer to the Section on Remote Commands for all available commands.
The calibrator may be controlled using commands and queries. All
commands may be entered using upper or lower case. The commands are
divided into the following categories:
Calibrator Commands
Only the calibrator uses these commands. For example
LOWER_MEAS DCV
tells the calibrator to measure voltage on the lower display.

3
Common Commands
Standard commands used by most devices. These commands always
begin with an "*". For example
*IDN?
tells the calibrator to return its identification.
Query Commands
Commands that ask for information. They always end with a "?". For
example:
FUNC?
Returns the current modes of the upper and lower displays.
Compound Commands
Commands that contain more than one command on one line. For
example:
LOWER_MEAS RTD; RTD_TYPE CU10
Sets the calibrator to measure RTD in the lower display and sets RTD
type to Cu 10.
Overlapped Commands
Commands that require more time to execute than normal. The command
*WAI can be used after the overlapped command to tell the calibrator to
wait until the command finishes before executing the next command. For
example:
TRIG; *WAI
Triggers the pulse train. Once the pulse train has been triggered, the
calibrator can proceed to the next command.
Sequential Commands
Commands that are executed immediately after the are entered. This type
includes most of the commands.
3.2 Character Processing
The data entered into the calibrator is processed as follows:
• ASCII characters are discarded if their decimal equivalent is less than 32
(space), except 10 (LF) and 13 (CR):
• Data is taken as 7-bit ASCII

4
• The most significant data bit is ignored.
• Upper or lower case is acceptable.
3.3 Response Data Types
The data returned by the calibrator can be divided into four types:
Integer
For most computers and controllers they are decimal numbers ranging from
-32768 to 32768. For example:
*ESE 140; *ESE? returns 140
Floating
Numbers that have up to 15 significant figures and exponents. For example:
CPRT_COEFA? returns 3.908000E-03
Character Response Data (CRD)
Data returned as keywords. For example:
RTD_TYPE? returns PT385_10
Indefinite ASCII (IAD)
Any ASCII characters followed by a terminator. For example:
*IDN? returns AMETEK, ASC301, 250, 1.00
3.4 Calibrator Status
Status registers, enable registers, and queues provide status information on
the calibrator. Each status register and queue has a summary bit in the
Serial Poll Status Byte. Enable registers generate summary bits in the Serial
Poll Status Byte. The following is a list of registers and queues along with
their function.
Serial Poll Status Byte (STB)
The STB is sent when the calibrator responds to the *STB? command.
Cleared when power is reset.
Service Request Enable Register (SRE)
Enables or disables the bits of the STB. Cleared when power is reset.

5
Setting bits to 0 disables them in the STB. Setting the bits to 1 enables
them. Bit assignments for the SRE and the STB are shown below.
76543210
0 MSS ESB 0 EAV 000
MSS
Master Summary Status. Set to 1 when ESB or EAV are 1
(enabled). Read using the *STB? command.
ESB
Set to 1 when at least one bit in ESR is 1.
EAV
Error Available. An error has been entered into the error queue,
and may be read using the Fault? command.
Event Status Register (ESR)
A two-byte register, in which the lower bits represent conditions of the
Calibrator. Cleared when read and when power is reset.
Event Status Enable Register (ESE)
Enables and disables bits in the ESR. Setting a bit to 1 enables the
corresponding bit in the ESR, and setting it to 0 disables the corresponding
bit. Cleared at power reset. Bit assignments for the ESR and the ESE
respectively are shown below.
15 14 13 12 11 10 9 8
00000000
76543210
PON 0 CME EXE DDE QYE 0 OPC
PON
Power On. Set to 1 if power was turned on and off before the
Event Status Register was read.

6
CME
Command Error. Set to 1 when the calibrator receives an invalid
command. Entering an unsupported RTD type may cause such
an error.
EXE
Execution Error. Set to 1 when the calibrator runs into an error
while executing is last command. A parameter that has too
significant figures may cause such an error.
DDE
Device-dependent Error. Set to 1 when, for example, the output of
the calibrator is overloaded.
QYE
Query Error.
OPC
Operation Complete. Set to 1 when the calibrator has finished
executing all commands before the command *OPC was entered.
Error Queue
If an error occurs due to invalid input or buffer overflow, its error code is sent
to the error queue. The error code can be read from the queue with the
command FAULT?. The error queue holds 15 error codes. When it is empty,
FAULT? returns 0. The error queue is cleared when power is reset or when
the clear command *CLS is entered.
Input Buffer
Calibrator stores all received data in the input buffer. The buffer holds 250
characters. The characters are processed on a first in, first out basis.

7
4. Remote Commands and Error Codes
The following tables list all commands, and their descriptions, that are
accepted by the calibrator.
Table 1: Common Commands
Command Description
*CLS *CLS (Clear status.) Clears the ESR, the error queue, and the RQS bit
in the status byte. Terminates pending Operation Complete commands
*ESE Loads a byte into the Event Status Enable register.
*ESE? Returns the contents of the Event Status Enable register.
*ESR? Returns the contents of the Event Status register and clears the regis-
ter.
*IDN? Identification query. Returns the manufacturer, model number, and firm-
ware revision level of the Calibrator.
*OPC Enables setting of bit 0 (OPC for "Operation Complete") in the Event
Status Register to 1 when all pending device operations are complete.
*OPC? Returns a 1 after all pending operations are complete. This command
causes program execution to pause until all operations are complete.
*RST Resets the state of the instrument to the power-up state. This com-
mand holds off execution of subsequent commands until it is com-
plete.
*SRE Loads a byte into the Service Request Enable register.
*SRE? Returns the byte from the Service Request Enable register.
*STB? Returns the status byte.
*WAI Prevents further remote commands from being executed until all previ-
ous remote commands have been executed.
Table 2: Calibrator Commands
Command Description
CAL_START Puts the calibrator in calibration mode
CJC_STATE Turns CJC on or off.
CJC_STATE? Returns the state of the CJC
CPRT_COEFA Sets the custom RTD coefficient A
CPRT_COEFA? Returns the custom RTD coefficient A
CPRT_COEFB Sets the custom RTD coefficient B
CPRT_COEFB? Returns the custom RTD coefficient B
CPRT_COEFC Sets the custom RTD coefficient C

8
CPRT_COEFC? Returns the custom RTD coefficient C
CPRT_MIN_T Sets the custom RTD minimum temperature
CPRT_MIN_T? Returns the custom RTD minimum temperature
CPRT_MAX_T Sets the custom RTD maximum temperature
CPRT_MAX_T? Returns the custom RTD maximum temperature
CPRT_R0 Sets the custom RTD R0 resistance
CPRT_R0? Returns the custom RTD R0 resistance
FAULT? Returns the error code of an error that has occurred
FREQ_LEVEL Sets the frequency and pulse amplitude
FREQ_LEVEL? Returns the frequency and pulse amplitude
FREQ_TYPE Set the frequency output to continuous (frequency) or pulse.
FREQ_TYPE? Returns frequency output type, continuous or pulse
FREQ_UNIT Sets the unit for frequency and pulse
FREQ_UNIT? Returns the unit for frequency and pulse
FUNC? Returns the current mode of the upper and lower display
HART_ON Turns the HART resistor on
HART_OFF Turns the HART resistor off
HART? Returns the state of the HART resistor
LOCAL Returns user to manual operation of the calibrator
LOCKOUT Locks out the keypad of the calibrator, and allows for remote
operation only
LOOP_PWR_OFF Turns 24V loop power off.
LOOP_PWR_ON Turns 24V loop power on.
LOOP_PWR? Returns the state of 24V loop power.
LOWER_MEAS Sets the mode for measuring on the lower display.
LT_START Begin a leak test
LT_STOP Stop a leak test
LT_INITIAL? Returns the initial leak test value
LT_FINAL? Returns the final leak test value
LT_RATE? Returns the leak rate
L_PRES_UNIT Sets the pressure unit on the lower display
OUT Sets the output of the calibrator
OUT? Returns the output of the calibrator
PRES? Returns the model and serial number of the attached pressure
module
PRES_UNIT? Returns the pressure unit for the upper and lower display