Western Reserve Controls, Inc.
1782-JDO User’s Manual
PRELIMINARY
10
The status/error byte represents the status of the communication command from the JDO to
the B1. This byte is defined as follows:
Table 2-2
Input Status/Error Byte
Table 2-3
Byte Value
(decimal)
Byte Value
(hex)
Meaning
0
0
No Error
1
1
Power-up Clear Command Expected*
2
2
Undefined Command*
3
3
TX Checksum Error to B1
4
4
Input Buffer Overrun*
5
5
Non-printable ASCII Character Received*
6
6
Data Field Error*
7
7
Communications Link Watchdog Time-out Error
8
8
Specified Limits Invalid
10
A
RX Checksum Error from B1
15
F
Optomux unit did not respond
* These are defined Optomux errors (Optomux error # + 1) that should never be seen with a
properly operating JDO.
4. Set up the JDO in your DeviceNet Master’s scan list.
5. Map your DeviceNet I/O between the JDO and the Master’s I/O image table or other
suitable file. (The JDO defaults to one B1 unit, so the JDO will send 3 bytes of data and
receive 2 from the Master.)
2.3 How to Write Serial Output Data to the JDO
1. Set up the receive size of your connection to equal the (
Max Number of B1 Devices * 2
)
in your Master’s scan table. This value is calculated by the JDO using the number of B1
devices you define in Parameter 4 and can be read from Parameter 6 in the Parameter
Object and the EDS file. The default value should be 2.
2. Map the data for your IO command to your scanners memory map.
i. The second byte contains the DI’s for channels 0-7.
ii. The third byte contains the DI’s for channels 8-15.
3. Direct the master to begin polling the JDO. The JDO will continuously issue Read Status
commands to the B1 and update the DeviceNet Poll Response (input data) with the input
data from the B1.
