87
9. Appendix C: Practical Example (RSLogix 500)
The various data used by the main program are shown in the following table:
Address Symbol Description
I:1.1/07 → I:1/23 ABC_HS_SEND Flip flop indicating that there is a new gateway diagnostic
O:1.0/00 → O:1/00 SCAN_V ALID ATIO N Enable DeviceNet communications: this bit must be set to 1 to validate the exchanges
O:1.1/05 → O:1/21 FB_DU Activation of Modbus communications by the gateway
O:1.1/06 → O:1/22 FB_HS_SEND Flip flop telling the gateway that there is a new command
O:1.1/07 → O:1/23 FB_HS_CONFI RM Bit used by the DeviceNet master to acknowledge diagnostics of the gateway
N7:0 MODUL E Parameter giving access (index) to the motor starter (called “module” to simplify things)
O:1.16 TRIGGER_OUT_RD_WR "Trigger bytes" used to trigger the emission of the read parameter request
(LSB) or of the write parameter request (MSB)
N7:36 ———— Local counter related to the “trigger byte” of the read parameter request
N7:37 ———— Local counter related to the “trigger byte” of the write parameter request
9.2. Controlling/Monitoring Sub-Program for a TeSys U Motor Starter: “LAD 3 -CMD_MON”
The role of this sub-program consists of exercising very simple control over one of the TeSys U motor starters,
depending on its current status and the user’s commands. The processes carried out in this sub-program are
described below, in the order in which they are run:
• Control of the motor to run forward / in reverse / to stop. Register N7:0 is used as a parameter. It contains
the number of both the input word and the output word used to control and monitor the TeSys U motor
starter. This same number is used to index one of the bits of each register for registers N7:32 to N7:35. The
input word used is located between I:1.2 and I:1.9 (motor starters nos. 1 to 8), and the output word used is
located between O:1.2 et O:1.9 (ditto). So the value of N7:0 must be between 2 and 9, according to the
number of the motor starter currently controlled.
The user controls the motor starter’s running mode using bits 2 to 9 (motor starters nos. 1 to 8) of registers
N7:32 ( Run (1) / Stop (0) ) and N7:33 (Run Forwards (0) / Reverse (1) ).
The forward, reverse and stop commands for the TeSys U motor starter are carried out under the following
conditions:
Bit 14 of a TeSys U status word = 0 ........ The motor starter is not in local mode.
Bit 02 of a TeSys U status word = 0 ........There is no fault on the motor starter.
Bit 00 of a TeSys U status word = 1 ........The motor starter is in the “Ready” or “Switched on” state.
When all of these conditions are met, registers N7:32 and N7:33 (bit 2 to 9, depending on the value of N7:0) are
used to control either the motor starter running forwards / in reverse, or to stop it by means of braking. The user
updates these two registers bit by bit, according to the commands he wishes to undertake.
• The faults on the TeSys U motor starter are reset. Register N7:0 is used in the same way as above and the
input and output words are the same as for controlling the motor starter.
When there is a fault on the motor starter (bit 2 of the monitoring register equal to 1), this fault is copied to
one of the bits 2 to 9 (one bit per motor starter) in register N7:34 (Faulty device (1) / Motor starter OK (0) ),
simply to show this state together with the user command which allows you to reset motor starter faults.
This user command corresponds to one of the bits 2 to 9 of register N7:35 (fault reset (1) ) and is used to
activate bit 3 of the command register of the corresponding TeSys U motor starter (“Reset” bit), that is to
say bit O:1.[N7:0]/3.
This fault reset user command is then cancelled by the program when the TeSys U motor starter no longer
shows that there is a fault.